The incident occurred Tuesday afternoon when the soldier went underwater in the lake and did not resurface, according to a press release. The Army did not provide a cause of death or the soldier's identity, which is typically withheld pending notification of next of kin.
A search for the soldier began Tuesday at Joe Swing Park Reservoir and included the base fire and emergency services, as well as the Tennessee Wildlife Resources Agency and Montgomery County Emergency Medical Services.
The park reservoir was shut down, and all military training in the area was suspended, the release said.
Army dive training is usually conducted with strict safety measures and consists of soldiers spending long periods of time submerged.
The incident marks the second dive training-related death this year.
Underwater Army training and missions are typically associated with Special Forces troops. Soldiers often graduate from the grueling seven-week Combat Diver Qualification Course, or CDQC, at the Special Forces Underwater Operations School in Key West.