The so-called Super Pond at Aberdeen Proving Ground (APG) is shut down until further notice.
When two Navy divers died at Aberdeen Proving Ground Tuesday, it was the second fatal water-based incident there in the last month.
A Nottingham man was killed on Jan. 30 in the pond while performing what APG said was "routine underwater test infrastructure maintenence."
Maj. Gen. Genaro J. Dellarocco, commanding general of the United States Army Test and Evaluation Command, issued a statement Wednesday that "the Super Pond is closed for investigation," reported The Baltimore Sun.
"The safety of all personnel working on APG and at the Super Pond is our number one priority," Dellarocco said.
The Super Pond is a 1,070-foot-long, 920-foot-wide elliptical underwater training facility, with a maximum depth of 150 feet.
Underwater, the military is able to test vessels, submarine systems and subsystems and munitions, torpedoes, missiles, warheads, amphibious vehicles and underwater gun firing.
The facility is also "capable of air blasts, air-to-water, air-to-ground, water-to-ground and ground-to-ground firings," according to a statement from APG.
As the military is conducting its own investigation into the fatalities at the facility, the public continues to search for answers.
Harford County emergency personnel told The Baltimore Sun that the divers in the Feb. 26 incident had been working on air hoses and were tethered to one another in the pond when they surfaced, both in cardiac arrest.
APG said in its initial statement that emergency officials responded at 2:30 p.m. to an "incident" in which two Navy men had been conducting a dive operation in the unexploded ordnance pond when one was killed. The second man was taken to Harford Memorial Hospital and pronounced dead, said officials.
According to The Whig, "a loud booming sound was heard and felt throughout the area" at 2:30 p.m. Tuesday, the time the "incident" reportedly occurred. The incident leading to the Jan. 30 death also took place at 2:30 p.m.