Navy investigates deaths of two divers in training pond

A test pond at Aberdeen Proving Ground in Aberdeen, Md. where two Navy divers with the Mobile Diving and Salvage Unit died Tuesday, Feb. 25, 2013. / AP/U.S. Army

The Navy is investigating the deaths of two divers during an operation at Aberdeen Proving Ground in Maryland, the second deadly incident at a deep pond there in the past month.

CBS Baltimore reports that the two divers that perished on Tuesday were 28-year-old James Reyher of Caldwell, Ohio and 23-year-old Ryan Harris of Gladstone, Mo. Both were members of a mobile diving unit based at Joint Expeditionary Base Little Creek-Fort Story in Virginia Beach.

The Navy says its Explosive Ordnance Disposal Group Two is conducting an investigation into the deaths, which they called "perplexing."

CBS Baltimore reports the two men were on a training dive when they were killed. Both had been communicating with the surface by tugging on a line. When these communications stopped, other divers went down and found them unresponsive.

According to the Baltimore Sun, both divers had been working in the pond using air hoses rather than self-contained breathing units. Both divers were in cardiac arrest when they surfaced.

Late last month, an engineering technician also died while performing maintenance at an underwater test pond at the Army site. The pond is used for a variety of tests, including shock testing of boat hulls.