A 25-year-old man was killed and a Fredericksburg man was injured yesterday when their pickup truck plunged 50 feet from a northbound Interstate Rte. 95 bridge into the Occoquan river, police said

The incident occured shortly before 2 p.m. after David Kuser, 25, of Fredericksburg apparently lost control of his truck and crashed through a guard rail, landing upside down in the waist-deep, 54-degree waters of the Occoquan, authorities said.

"we tried to get a boat launched from a marina 600 yards from the crash but the marina wasn't usable," said Lt. Edward Rahl of the Prince William County Fire and Rescue Services. "one of the victims managed to pull himself out of the truck, but a police diver found the other guy partially submerged about 15 feet away from the truck."

Authorities withheld the identity of the dead man pending notification of relatives.

Ryan Wojtanowski, 27, was filling a boat with gasoline at a nearby gasoline station when a woman ran onto the lot screaming that people were trapped inside a truck in the river.

"it was about 18 feet from shore and the cab was crushed. The water was waist deep on the shore side but was a lot deeper where they found the second guy."

Kuser was being treated for shock and dislocated shoulder at Potomac Hospital in Woodbridge yesterday, a nursing supervisor said. Officials were unable to ascertain whether the second victim died of drowning, or from injuries sutained in the crash.

Prince William County police at the scene were at a loss to determine how the crash occured, but said that no other vehicles were believed involved in the accident.

"it's still under investigation at this point," said Prince William County police officer.