A gunman held police at bay in West Philadelphia yesterday afternoon during an hour-long standoff before fatally shooting himself in the head, police said.

Police blocked off a large area around 45th and Market Streets after the situation began, about 11 a.m. Police said that the man had been involved in a car accident on Chestnut Street and that his vehicle hit a parked car as he drove off. His car then struck a utility pole at 46th and Market.

Police on patrol encountered the man, who got out of his vehicle, sat on the sidewalk, and put the barrel of a pistol into his mouth, police said. Traffic was stopped in all directions as SWAT officers rushed to the area. For about an hour, negotiators tried to persuade the man to surrender. Shortly after noon, however, he shot himself in the head. He was taken to the Hospital of the University of Pennsylvania, where he was pronounced dead shortly after arriving.

Police said the man, whose name was withheld pending notification of relatives, was distraught for reasons beyond the car accident.

- Barbara Boyer