Six weeks after the unexplained death of a 12-year-old girl on a scuba training course, investigators who failed to collect dive-computers at the scene appear still not to have analysed the data available from them – and one of the two dive professionals’ units is reported to have gone missing.
Prominent US lawyer, diver and explorer David Concannon, who has litigated in many diving-related cases, is giving his services pro bono to the family of Dylan Harrison from Rockwall, Texas. He has expressed concern that two months on they remain in the dark as to how and why their daughter died.
UPDATE: Also read Fall-out continues from Dylan’s diving death
Kaufman County sheriff’s officers failed to retrieve and analyse data from the dive-computers worn by Dylan, her instructor, the divemaster and one of the other trainees in the group, according to a Fox News report on the incident.
The unit belonging to one of the two dive professionals present is since said to have been lost in a 27m-deep lake. The diving instructor, William Armstrong, is an assistant chief deputy with Collin County sheriff’s office.
Miscommunication
The class at which Dylan hoped to secure her open-water certification was held at the Scuba Ranch, a privately owned inland site in Terrell, Texas, on the morning of 16 August. The session was being run by Scubatoys.com of Carrollton, which claims to be one of the biggest dive-shops in the USA.
Dylan had been looking forward to diving with her father and grandfather at the lake after getting certified.
Concannon has contacted other divers present on the day and says that Dylan was one of eight students accompanied by Armstrong and the unnamed divemaster.
They descended to a 5m-deep platform, but after what Concannon describes as a “miscommunication between a student and the instructor” the trainee went to the surface, and Armstrong is said to have brought the other divers up.
They then redescended but, while Armstrong and the divemaster say that they all filed down a descent line, at least one of the students has stated that everyone had descended at once. This is where the computers could provide definitive answers, says Concannon.
Once back on the platform, a headcount revealed Dylan to be missing. Members of the Dallas County sheriff’s office dive-team who had been training at the lake launched a search and found the girl at a depth of about 13m, some way from the platform.
‘All available evidence’
Kaufman County sheriff’s office says that the incident remains an open criminal investigation while “all available evidence” is followed up. Concannon, speaking to Fox News in mid-October, insists that he had been telling the office since early September that the dive-computers were key to the investigation.
“This is the first case I’ve had, out of almost 300, where answers have not been forthcoming, and evidence was not gathered at the scene or shortly thereafter, by the people who know what to do,” says Concannon.
Likening failure to consider dive-computer data to ignoring the black box after a plane crash, he said: “If you are responsible for investigating the death of anyone, but especially a child, you should give those families answers as soon as you possibly can.”
UPDATE: Also read Fall-out continues from Dylan’s diving death
UPDATE 28 October 2025: Armstrong resigns, NAUI speaks.
It’s very strange that so many things were ignored and yet a police deputy was the instructor. You would think he would have been the first to step up. Something is not right here. My heart goes out to those parents. They deserve the truth. Someone needs to do the right thing and speak up.
They dobt want to be sued and be liable so they are protecting the person responsible.
Please review the person who found Dylan’s body @ https://www.yahoo.com/news/articles/scuba-expert-witnessed-ntx-12-214934497.html
Richard Thomas is the owner of International Scuba in Carrollton and an expert in this field and if you listen closely to his account of the how he discovered Dylan in 7 minutes, he’s telling us exactly what everyone suspects. Outside LEO needs to be called in ASAP for this case. There is a direct conflict of interest as one of the “professionals” responsible for a 12 year old’s life is also a county sheriff.
My heart breaks for the family of this young girl. I pray they leave no stone unturned on this case because it is blatantly being covered up by local LEO. A child died and you’re on the shore dry! You don’t even identify yourself to someone willing to go try to find Dylan?? As a mother, I’m furious over the audacity of these good ol’ boy shenanigans! COLLIN COUNTY, TEXAS DEPUTY ASSISTANT CHIEF WILLIAM ARMSTRONG is hiding behind a badge and his buddies are helping him. She was a baby in that cold dark water!
Not unexplained!
8 students to 1 instructor is criminal!
PADI’s rules have been WRONG for decades! That instructor should be hung for incompetence!
I’m an instructor since 1978 and know 4 students to one is the very limit with a very seasoned instructor! No computer will be of any help when it is obvious the instructor was totally 100% wrong for not being at arms length distance from ANY student. PADI has to change the ratio’s. I am available to help this family get justice for such blatant incompetence. This should NEVER have happened.
I’m a 3 star CMAS instructor and I wouldn’t dream of trying to teach a 12 year old to scuba dive..NOT to mention the liability issue
Jim Quail Oshawa Ontario
This is so, so wrong, how can you firstly lose a student diver on the surface, miss a head count and the worst of all, not collecting the dive computers from the deceased and the instructors. This sounds totally wrong from the outside looking in.
My thoughts and prayers are with the family at this tragic time, I hope they get the answers they deserve asap.
PADI = PASS ANY DIVER IMMEDIATELY /PUT ANOTHER DOLLAR IN , I WAS TRAINED BY NAUI /FAUI instructors in the late 1980s , been diving for 36 years.
See so many idiot instructors, no common sense .
I have seen dive schools in ocean conditions i would not venture into 😬. So sad , scuba is fabulous , still do 100 plus dives a year at 75 🫠🙃🙂.
I concur with many comments , i have argued on livaboards re diving protocols in big sea conditions ….HERE IN AUSTRALIA on GBR 😵💫😵💫😵💫😵💫.
It was a NAUI class… 🫠
Bite me. You’re so full of yourself that you didn’t even read it was a NAUI INSTRUCTOR DOING A NAUI CLASS. But it makes sense. NAUI always shits on PADI; I’ve been PADI since before YOU were NAUI and the worst fuck ups I’ve seen have been overconfident “big bad ass” NAUI instructors who think they are the shit. Like taking a fresh crop of people right after their Cert dive on a 75 ft wreck dive with penetration in Florida. Boat owner/Dive operator nearly KILLED that instructor (a NAUI STUDENT OF HIS) when he found out the brand new divers this NAUI instructor had with him had just been certified a day or two before. But that’s just like you to jump to conclusions when you haven’t even read what you’re talking about.
Yes , you are partly right re being full of myself and PADI SHIT , so glad SSI almost shut Padi down, both FAUI and NAUI were shut down by PADI in mid 1980s in Australia .
And PADI’S PUT ANOTHER DOLLAR IN business template has resulted in only 4 of the 48 dive shops of the 1990s are still in business.
My experiences are of PADI /NAUI/ FAUI in Australia in the 1990s and PADI in the south west pacific , all around AUSTRALIA , SOUTH /CENTRAL AMERICA , RED SEA , INDIA OCEAN , MEDITERREAN , CARRIBEAN , over the last 33 years never dived the U.S and not likely to with the spoilt brat aka herr donald.
PS still a shit situation for this young girls family and SADLY I HAVE PADI CERTIFICATIOS as CMAS not big in AUSTRALIA , NAUI / FAUI gone and SSI 10 years away.
Why was the young girl buddy with another 12 year old..Why was she not buddy with her father or grandfather??
Im iantd and padi rescue diver ..with someone that young on an open water course ,why didn’t they have a dedicated rescue diver? On the courses I’ve been on with young people, there would of been a rescue diver or dive master behind them /over them with in touching distance.
I was an instructor for 30 years with SSI in Colorado. 4:1 ratio unless Dive master or Divecon assisting. I question the visability in the lake. Concur with all previous comments as well.
If the the visibility is an issue, all the more reason for extra supervision and the support staff to be closer. Im from the uk where inland diver training sites can easily have less than 2 meter visibility. Hence I would expect a much closer supervision.
A12-year old child should not be scuba diving. As a parent, it’s highly irresponsible to allow them to engage in the activity.
However, the points made about the dive computers are totally valid. I grieve the family despite the parents’ negligence with this inherently dangerous activity.
This was gross negligence and incompetence by the instructors and institution that led the course, NOT the parents who trusted them with their child.
Are the parents responsible if they allow their kid to go swimming at the deep end of a pool with life guards on duty? (who just failed to like, do their job?)
If the 12 y/o was diving alone, yes, but that simply wasn’t the case. She was diving with certified instructors. If you want to blame someone, blame the assistant deputy withholding information along with the institution.