Crews search for Las Vegas man missing at Lake Mead

A Las Vegas man who disappeared while swimming in Lake Mead on Tuesday evening is presumed to have drowned and has been identified as Ruben Aguirre-Martinez, an official with the National Park Service said Wednesday.

Andrew Munoz, Park Service spokesman, said Aguirre-Martinez, 38, went missing about 7:30 p.m. near Callville Bay.

Crews began patrolling about 6 a.m. Wednesday and stopped at 4 p.m. Rangers will continue the search today .

"Given the witness reports, how long he has been missing, the water temperature, and weather conditions, we believe that the probability of finding Aguirre-Martinez alive is very unlikely," Munoz said in a statement.

If Aguirre-Martinez has not been located by Friday, the search will be scaled down to regular patrols of the area.

Munoz said two men were in a boat pulling another man on an inflatable raft. The men in the boat jumped in the water to help the man on the raft get on the boat, but the raft and the boat then floated away.

Two of the men shared a life jacket and were rescued by a passing boat, but the third man disappeared.