Anatomy of a Dive Death

Ken Kurtis led the panel "Why Divers Die" at the Scuba Show in Long Beach earlier this summer, about dive fatalities in Los Angeles County in 2013. Kurtis, owner of the dive shop Reef Seekers in Beverly Hills, is also the scuba consultant to the Los Angeles County Department of Medical Examiner-Coroner, which has had this position since the 1950s (UCLA professor Glenn Egstrom, a dive research pioneer, was the first, and held that spot for 40-odd years). Because coroner reports in Los Angeles County are public record, starting in the mid-2000s, the department gives a public accounting of the fatalities occurring in its jurisdiction. In this article, Kurtis describes how the department handles investigations and uses evidence and deduction to come up with rulings, then provides a sample of cases it handled last year.

In Los Angeles County, all dive deaths are initially treated as a possible homicide, so one of the Sherriff's first tasks is to make a determination in that regard. The responding sheriff takes control of all dive gear, takes witness statements, may test the gear or turn it over to the Medical Examiner-Coroner, and then transports the body to the ME-Corner's facility. Coroner investigators will conduct their own interviews and receive copies of reports from the various first responders, while Coroner physicians perform an autopsy that includes toxicology screening. The ME-Coroner's goal is to determine the cause of death within reasonable medical certainty. You could have two people look at the same autopsy and test results and come up with two different opinions, so it's important to remember that what the Coroner is producing is an informed medical opinion, based on the evidence available at the time. Its conclusion is not an assessment of legal responsibility.

From a diving standpoint, a Coroner's finding does not always tell us much. While "drowning" may indeed be the medical reason for the death, it is a sometimes unsatisfying conclusion to divers looking for answers. Divers Alert Network (DAN) has come up with a four-step process that involves:

1) Trigger -- what got everything started;
2) Disabling event -- what the trigger caused to happen;
3) Disabling injury -- produced by the disabling event; and
4) Cause of death.

One of our cases involved a 14-year-old child whose official cause of death was listed as drowning, but when we applied the DAN model, we got:

1) inability to clear water from the mask;
2) bolting for the surface while holding breath;
3) embolism; and
4) drowning.

Even though the cause of death is still the same, from a diving perspective, it's now a more complete picture.

Multiple Choices? Use Occam's Razor

None of this is black and white. Most diving fatalities happen outside the direct view of someone else. This can be because of inadvertent buddy separation, solo diving, or simply that the buddy was not looking in the victim's direction when everything went south. We sometimes say that the dive computer is the only unbiased witness in any diving fatality investigation, but even then, it doesn't give us a complete picture. The computer may not be downloadable, or perhaps the memory chip overwrote itself if the victim was underwater and not recovered for a long time, or it was mishandled. So we also have to rely on the statements from others who were there, the physical evidence that can be recovered and what can be gleaned from that, and our own experiences and intuition about how divers dive and what may have happened.

We had a case years ago where the accident happened at the beginning of the dive. The victim was recovered from 50 feet, with his leg entangled in the anchor line of his boat. His tank was full, but his air valve had been turned off, and he wasn't wearing his weight belt. What happened? Karl Huggins, director of the Catalina Hyperbaric Chamber, and I are both fond of the principle of Occam's Razor: When faced with multiple hypotheses, generally the simplest one will be closest to the truth. In this case, the simplest theory was that, before the dive, this guy turned on his air, checked it, then turned it off and eventually jumped in without turning it back on. However, the other people on the boat swore there was no way this had happened, that no one saw him turn his air off, that he wouldn't do that, that he was experienced, etc.

So we first tested the theory of whether he could have gotten to depth on "no" air. It seemed possible, as our surface tests showed about six breaths of air may remain in the hose of a regulator if the tank valve had been turned on and then off. Then, with a pony bottle under my arm and a buddy with an octopus at my side, I did a practical test in the ocean, using the same gear with the air turned on and then off. I made it down to 47 feet. So it seemed our theory had some merit. Now we had to find evidence to support it, despite what his friends on the boat said. After talking to others he dived with, we found a couple of dive buddies who said he not only did that all the time, but they had also seen him forget to turn the air back on. He would just reach back and open the valve underwater once he'd sucked all the air out of the hoses and realized his air wasn't on..

Because the tests and interviews supported our theory, it seemed a reasonable assessment of what had transpired.

Trigger: Turning off the air.

Disabling event: Breathing all the air out of the hoses and not being able to turn the air back on.

Disabling injury: (moved down from above row)Anchor line entanglement, with possible loss of weight belt while attempting a free ascent, resulting in water inhalation.

Cause of death: drowning.

A lot of this comes down to diver error. A few years ago, I looked at three years worth of DAN reports (347 fatalities) and came up with 69 percent as the number of fatal dives in which diver error played a significant -- and deadly -- role. If divers made better decisions, paid closer attention to our air and stayed on top of our medical issues, we could eliminate a lot of scuba deaths overnight. You will see these three things factor in to the four Los Angeles County fatalities from 2013.

Case #1: Toughing It Out Instead of Sitting It Out

A 54-year-old man, who had earned his basic openwater certification 10 months earlier, was diving the Sujac wreck near Catalina Island with an instructor and a buddy. It was their second attempted dive of the day; his first dive was a struggle, and he aborted after only a few minutes, at 20 feet. He and his buddy took a two-hour lunch break and returned for a second attempt, but he was reportedly winded at the top of the entry stairs, as well as at the bottom. While snorkeling out to the wreck's descent buoy, he became unresponsive on the surface and was extricated from the water by a Harbor Patrol boat. CPR was started, and he was transported to the Catalina Hyperbaric Chamber, but was pronounced dead upon arrival.

His medical history included high cholesterol, high blood pressure, heavy smoking and experimental drug abuse in the past, and obesity. His autopsy revealed a heart weighing 650 grams ( anything over 400 grams is considered problematical). Cause of death: Acute cardiac dysfunction, due to a weakening of the heart that eventually leads to heart failure). This was ruled death due to natural causes. In other words, it was his time and he just happened to be in the water.

My take on this: There are just some times when you shouldn't dive. Problems descending on the first dive followed by being winded at the start of the second dive might give you pause. Sometimes the thinking process needs to be, "I'm going to sit this one out" instead of "I can tough this out." There's no saying the outcome would have been any different, but if a diver has any cardio-related issues, he or she probably has a better chance of surviving if the issues occur on land rather than in the water.

Case #2: Was He Fit Enough to Freedive?

A 44 year-old man was freediving and spearfishing with a buddy at Terranea Resort in Palos Verdes when he shouted that he was having trouble breathing. He pulled himself on to the rocks and became unresponsive. The buddy began CPR, but when paramedics arrived, they pronounced him dead. His medical history included hypertension, high cholesterol, and a heart attack seven months earlier. The autopsy revealed a 500 gram heart, severe hardening of the arteries in the abdominal aorta, and 85 to 95 percent blockage of the coronary arteries. Cause of death: atherosclerotic cardiovascular disease, and a ruled death due to natural causes.

My take: Again, it's a question of being aware of your fitness level and if the dive is an appropriate one to make. Freediving, especially when spearing fish, can be very taxing, even for someone in good shape. But factor in a heart attack seven months prior and perhaps it's an activity that diver should have reconsidered.

Case #3: Accidents Can Happen in an Instant

A 60-year-old man was diving with a buddy at White Point, Los Angeles. He had been certified over 30 years ago, but the last time he went diving was unknown. He and his buddy aborted their first attempt at entry, due to rocky conditions and the buddy losing a fin. During their second attempt, the victim was placing a float with a flag in 20 feet of water but the buddy was uncertain if he ever submerged or simply dropped the weighted float line to the bottom. At some point, the victim called out for help and became unresponsive. He was extricated from the water and bystanders began CPR. He was transported to a nearby hospital and pronounced dead in the ER. Autopsy revealed only 25 percent blockage of the coronary arteries, which is not at all bad for a man his age. The cause of death was listed simply as drowning.

My take: This case underscores how accidents can happen in an instant. But it also points out the difficulty in trying to ascertain exactly what happened. The buddy is certain the victim never submerged, but when we looked at his dive computer, a non-air-integrated U.S. Divers Matrix, it clearly showed the last dive was made to a depth of nine feet for zero minutes. The time is easy to explain because the Matrix shows hours and minutes but not seconds. That means it doesn't register "0:01" until 60 seconds have elapsed, so you could do a dive for up to 59 seconds and it would still register as "0:00." But the Matrix also does not time/date stamp dives, so we have no way of knowing when this last dive actually occurred. And it was not downloadable, so all we could do is look at the display. Had this actually been his last dive, he might have descended to nine feet, had a problem and panicked, held his breath on ascent, embolized and then screamed for help when he surfaced. The buddy was putting on his fins and not facing toward the victim, so it's possible. But the buddy was fairly certain that the victim never went underwater, so we're left with the other possibility of him inadvertently gulping water at the surface, which caused an adverse reaction and led to his death. While an embolism can be detected at autopsy, vigorous CPR can also cause the same tissue damage as an embolism would. So it's difficult to say exactly what happened.

Case #4: Were Lobsters More Important than Air Supply?

A 60-year-old male went lobster diving with a buddy at Dockweiler State Beach. While 250 feet from shore, and diving inside a support structure that is underneath an intake water pipe, he became separated from his buddy. The buddy returned to the beach and called for help. Dive rescue teams located his body wedged in that enclosed structure under the pipe. Due to dangerous surface conditions and the difficulty of extrication, plans were made to recover his body the next day. When rescuers returned, they discovered his body floating at the surface offshore, but without any gear. His body was recovered, but, due to still-dangerous conditions, no attempt was made to retrieve his gear. Autopsy revealed 50 to 75 percent blockage of the coronary arteries. Cause of death: drowning with underlying atherosclerotic cardiovascular disease.

My take: Because the gear was never recovered, we couldn't test it. However, he was wearing a downloadable air-integrated wrist computer, so we were able to view the profile of the fatal dive. It shows a gradual descent down to 35 feet, then the depth bounces rhythmically between 35 and 33 feet. Because he was in an overhead environment that didn't have a lot of height, this depth fluctuation could simply be a result of waves passing overhead. What was most striking was the air consumption portion, which shows a fairly steady and regular decrease in the air supply to the 47-minute mark, seemingly indicating a normallybreathing diver up to the point where he exhausts the air supply. Even then, there doesn't seem to be an increase in the rate of breathing, which you might expect to see if someone knew they were stuck and running out of air. The evenness of the air supply graph could indicate someone so intent on hunting for lobsters that he wasn't closely watching his air, and inadvertently ran out. Because he was in an overhead environment, there's no way to reach the surface. So while we can construct possible scenarios, it's impossible to say with certainty which one is what happened.

The goal in publicly presenting these cases is with the hopes that you will examine your own diving behaviors, and, if you see some parallels, perhaps rethink the steps you can take to insure that you do not appear in one of Undercurrent's "Why Divers Die" articles.