Background: The Scuba Ranch training lake in Terrell, Texas (KDFW). Inset (left): William Armstrong (Kaufman County Sheriff”s Office). Inset (right): Dylan Harrison (lawsuit).
An unsettling incident has unfolded in Texas where a family is pursuing justice following the tragic drowning of their 12-year-old daughter, Dylan Harrison, during a scuba diving class. In a recent development, William Armstrong, a former assistant chief deputy from Collin County, has been apprehended and charged with felony injury to a child. Armstrong was the certified scuba instructor responsible for overseeing Dylan’s diving certification class on August 16, 2025, alongside certified divemaster Jonathan Roussel.
During the ill-fated session, Dylan went unnoticed for a period, only to be discovered unresponsive over 30 minutes later. Despite immediate medical intervention, she was pronounced dead by emergency personnel at the scene, leaving her family devastated and demanding answers.
In the wake of this tragedy, Dylan’s family has initiated a lawsuit targeting Armstrong, Roussel, the National Association of Underwater Instructors, and other entities involved with the scuba course. The family had enrolled Dylan in the class and purchased necessary equipment from Scubatoys, located in Carrollton, Texas. This establishment also hosted an initial class before moving the group, which included eight students and two instructors, to a lake at The Scuba Ranch for practical training.
Both Scubatoys and The Scuba Ranch have been named as defendants in the lawsuit, reflecting the family’s pursuit of accountability across all parties involved.
The lawsuit further reveals that Armstrong, apart from his primary role at the Collin County Sheriff’s Office, held a secondary job as a security guard. On the day preceding Dylan’s class, he reportedly worked a full daytime shift followed by a full overnight shift, leaving him with minimal rest before the critical class. This lack of sleep is cited as a contributing factor to the oversight during the session.
According to legal documents, when it became apparent that Dylan had separated from her peers, Roussel took the remaining students to safety on shore while Armstrong conducted a search on land. Simultaneously, emergency services were alerted, and additional divers and staff at The Scuba Ranch joined the effort to locate Dylan. Despite these measures, the search ended in heartbreak.
However, “Armstrong and Roussel were seen leaving the area and, when they returned, they were reportedly unhelpful in guiding the search for [Dylan]. Consequently, the initial search was disorganized and inefficient, wasting valuable time.”
Local Fox affiliate KDFW reported that Armstrong resigned from his position at the Collin County Sheriff’s Office in October. Scubatoys closed its doors on Jan. 31.
Armstrong was charged with felony injury to a child on Friday. After he was booked into the Kaufman County Jail, he posted a $150,000 bond and was released. His next court date was not available.
