Prince George's County police and fire officials are investigating the death early yesterday of an 18-year-old probationary member of the Clinton Fire Company who they said consumed a large amount of alcohol and was found unconscious in her car outside the firehouse.

Pamela Diane Bellani, of 6812 Woodland Rd., Morningside, was pronounced dead on arrival at the Southern Maryland Hospital Center shortly after midnight yesterday morning, police said. Clinton Fire Chief Aubrey Schultz said she apparently choked on her vomit as she sat in her parked car.

Bellani's stepfather, Larry Phipps, said he was told by a police detective yesterday morning that Bellani had consumed a fifth of whiskey in about a one-hour period.

Neither the doctor who examined Bellani nor homicide detectives investigating the case could be reached for comment yesterday.

Bellani's body has been taken to the medical examiner's office in Baltimore to determine the exact cause of death.

Bellani's parents and friends said yesterday that she seldom drank and that they found it hard to believe that she had consumed a fifth of whiskey. "I know Pam wasn't a drinker," said her stepfather. "I had heard she drank a fifth in an hour. I'm a drinker and I couldn't drink that much myself."

Schultz, volunteer chief of the Clinton station for about 30 years, said records show Bellani signed in at the station at 6:45 p.m. Saturday. Sometime that evening, Schultz said, Bellani, "being new and wanting to be one of the boys," asked to go along with three male volunteer firefighters to play pool at a house nearby. She did not sign out, as is the custom at the station, Schultz said.

Schultz said he has discussed Saturday night's events with the three volunteer firefighters who accompanied Bellani, but he would not identify them yesterday.

Schultz said he has been told by Bellani's companions that she was the only one of the group drinking at the house. He said at least two of the firefighters were under the legal drinking age.

"They just said she just turned [the bottle] up and started drinking and in no time had drank the whole damn bottle," said Schultz.

"I don't know what was happening," he said yesterday during an interview at the firehouse on Woodyard Road. He said he plans to question the three firefighters further.

Schultz said that when the group returned to the firehouse, they did not bring Bellani inside because of a strict rule against drinking or being drunk in the firehouse. Instead, he said, "She got in her car and tried to go to sleep."

He said her companions wanted to drive her home and went to get her address from the sergeant in charge. One companion brought her a blanket, he said. "She didn't look good, so they went in and got the medic," he said.

Schultz said the medic then woke a second medic, who was asleep upstairs, and they rushed Bellani to the hospital. He said he was unaware of what, if any, treatment was administered to her at the firehouse.

Schultz said he arrived on the scene shortly after midnight. By then, he said, police had towed away Bellani's car as evidence.

Schultz said that Bellani had applied to be a volunteer firefighter Feb. 3 and was given probationary status Feb. 10. He said she had been receiving emergency medical and cardiopulmonary resuscitation training at the county's fire academy in Cheltenham in southern Prince George's.

He said she had been at the firehouse only four previous times, for a total of about 20 hours.

Friends and family described Bellani yesterday as an exceptional student at Central High School in Capitol Heights, from which she was to graduate this spring. They said she was also attending Prince George's Community College and planned to enter the University of Maryland in the fall.

"She just wanted to help people," her longtime friend Kim Edelin said yesterday. "That's all she wanted to do. Save the world."

She had applied to join the Clinton company, her mother, Barbara Phipps, said, because it had an ambulance unit and "she said it was run most professionally, that the fire chief was strict. She talked about the training. She really liked the classes and was learning a lot."

Bellani's boyfriend, Steve Stampfer, 19, a maintenance mechanic at the National Institutes of Health, had applied with Bellani for membership in the Clinton company.

Stampfer, who said he has been a volunteer member of another fire company for three years, said the Clinton station is known for being "really strict on safety . . . . If you mess up, you're gone."

The Clinton station is known in firefighting circles as "the house of chrome" for its spiffy engines and chrome-plated fire hydrant.