Updated at 3:25 p.m.

Authorities believe that a Reston man who jumped off a cliff into the Potomac River and did not emerge has died.

Montgomery County police spokesman Paul Starks and fire and rescue spokesman Pete Piringer said that the man is presumed drowned. Crews continue to search the river for the 21-year-old’s body.

Starks identified the man on Thursday as Marco Reyes-Sanchez.

Piringer said that two cliff divers in their 20s went into the water on Wednesday from the Virginia side, near Sandy Landing. Only one came out.

The search began before 2:30 p.m. Wednesday. About three hours later, workers suspended their search for the night and then resumed Thursday.

Piringer said that U.S. Park Police officers assisted with Wednesday’s search by helicopter and with Thursday’s efforts on foot and on horseback.

Julie Zauzmer contributed to this report.