A 19-year-old Arlington man was missing last night and presumed drowned after he fell into the Potomac River while fishing at the base of a cliff south of Great Falls Park in Virginia, Fairfax County fire officials said.

Two men who were fishing with the missing man were pulled to safety in what authorities described as a dramatic nighttime rescue effort.

Officials identified the missing man as Hai Van Huynh. They said he and two companions were fishing with nets when he and one of the other men fell into the swiftly moving waters and the third man then dove in after them.

Huynh disappeared, but the other two men managed to pull themselves on to rocks below a scenic overlook south of the park, the officials said.

A park ranger, illuminated by the searchlight of a Fairfax County police helicopter hovering nearby, descended with ropes 80 feet down the cliff to where they were stranded and a rescue team at the top of the cliff pulled them to safety, Fairfax fire officials said.

Rescue workers from fire units in Montgomery and Fairfax counties, as well as U.S. Park Police, broke off their search for Huynh around 9 p.m., about two hours after the accident occurred. The two men with Huynh were identified as his housemates, brothers An Ngoc Le, 25, and Loc Thanh Le, 17.

Huynh's disappearance was the latest of several recent incidents involving the river, some of them fatal.

Park Police yesterday recovered the body of an unidentified man from the river south of Great Falls Park in Maryland.

Also yesterday, Montgomery County police identified a body recovered from the river Saturday as that of James Skowronski, 19, of Fairfax. Skowronski had been missing since April 21 when he and two companions tried to swim from Virginia to Maryland.