NTX scuba death: Former deputy worked all day, overnight before instructing class, officials say

Instructor in NTX scuba death broke protocol: Expert

The Collin County Sheriff's Office confirmed that after working all day, former Assistant Chief Deputy William Armstrong then worked an off-duty job all night Friday and into Saturday morning.

TERRELL, Texas - Disturbing new information has surfaced about a scuba instructor's work hours prior to the death of a child during his scuba class in Terrell.

The Collin County Sheriff's Office confirmed that after working all day, former Assistant Chief Deputy William Armstrong then worked an off-duty job all night Friday and into Saturday morning.

Dylan Harrison's scuba class started just two hours later. Soon after, the 12-year-old drowned after being separated from her class.

New NTX scuba death details

William Armstrong

The latest:

Armstrong took eight lives into his hands, Saturday, Aug. 16.

Now, FOX 4 has learned that he did it after working a full day for the Collin County Sheriff's Office, and then a full night and morning at Fisher Investments in Plano from 9 p.m. Friday, Aug 15, to 6 a.m. Aug. 16.

Armstrong resigned from the sheriff's office after FOX 4 reported about the death of Dylan during his open-water class, which was run by Scuba Toys.

In one report, a witness said Armstrong was out of the water and dry before Dylan was found lifeless at the bottom of the lake.

Fisher Investments tells FOX 4 Armstrong was working for a third-party company the night before the class.

"William Armstrong did not work for Fisher Investments as an employee or contractor—like many businesses, we outsource various services to third-party companies which supply their own staffing, scheduling and supervision," the company said in a statement.

Break of scuba protocol

What they're saying:

Ross Neill is a course director for scuba instructors in Key Largo, Florida. He said that was a break of protocol, noting that the instructor should be the first one in and last one out of the water during a class.

"Why did he surface without all divers?" Neill asked. "That should be looked into."

Neill also wonders why Armstrong would think it was okay to work a full day, a full night, and then take on another full day instructing a scuba class immediately after.

"The importance of rest when it comes to anything we do is paramount," Neill said.

"I would say the same thing to an airline pilot getting ready to go into the cockpit with little sleep," he continued.

After leaving his job at Fisher Investments at 6 a.m., he then reportedly had a drive of more than an hour to the Scuba Ranch.

Video of Dylan getting in the water was taken at 8:33 a.m.

"We can't be expected to take care of others if our own well-being is not taken care of," Neill said. "At the end of the day, water is going to win if we are not vigilant."

Divers Alert Network, the insurance company for Armstrong, declined to comment on the investigation.