One man was killed and 18 other persons were injured yesterday when a dump truck crashed into the rear of a van and set off a chain reaction accident at Route 301 and Cedarville Road at the southern tip of Prince George's County, authorities said.

Several passengers, including the man who was killed, were trapped in the van and had to be removed from the wreckage by rescuers from Prince George's and Charles counties, according to Maryland State Police spokesman Bill Clark. The rescuers worked for more than 20 minutes to free the victims, Clark said.

The dead man was identified as John Reynolds, 66, of Elmsford, N.Y., a passenger aboard the van. A medical examiner reported that he had been crushed in the crash and suffered internal injuries.

The accident occurred, police said, when the dump truck, driven by William A. Cooper, 21, of Upper Marlboro, crashed into the back of the van. The force of the crash pushed the van into a pickup truck, which then hit a car. Neither Cooper nor the car's occupants were injured.

The van was carrying students from the Harry Lundeberg School for Seamanship in St. Mary's County who were returning from their workday at the Seafarer's International Union in Camp Springs, according to a school spokesman.

Cooper was charged with failure to reduce speed to avoid an accident, according to Clark, who said Cooper told authorities the accident occurred when his accelerator pedal stuck.

The crash victims were taken to three area hospitals. Two were flown from the accident site by police helicopter to the shock trauma unit of Prince George's General Hospital in Cheverly after being freed from the wreckage.