Two teenage girls and a 25-year-old man were killed Wednesday morning when their car rear-ended a parked tractor-trailer on a busy two-lane road in Brentwood, Suffolk police said.

The 6:18 a.m. accident on Suffolk Avenue near Nimitz Avenue killed driver Araceli Carpenter, 19, of East Patchogue, and passengers Meagan Ferraro, 17, of Islip, and Stephen Nowakowski, 25, of Ronkonkoma, police said.

The 1995 Ford Escort they were riding in was severely damaged by the impact. The driver of the parked truck, who had been sleeping inside the cab, was not injured, police said.

Meagan Ferraro's family members said they reacted with disbelief when they were told she had been killed, just over a week after celebrating her 17th birthday May 5.

"I thought I wasn't hearing it right," said her father, Joseph Ferraro, a commercial fisherman. "My son said, 'Meagan's been in an accident. Meagan's dead.' What did you say? Dead? What? I didn't want to believe it."

Her mother, Donna Ferraro, said she screamed when she heard the news.

"I don't know whether we're ever going to be the same again," she said last night. "She was a good girl. She loved her family more than life itself."

The Ferraros said that, at the time of the crash, Meagan was returning home after having spent the night at the home of a friend whom she had given a birthday present.

The other victims' families could not be reached for comment.

Up to 20 young adults held lighted candles and gathered last night around a tree near the site of the crash. They hugged each other and placed the candles and some pictures of the victims at the site, forming a makeshift shrine.

Ramon Reyes, 54, a Suffolk Avenue resident, said the truck had been parked on the street at least as early as 1:30 a.m. when he came home from his job as a restaurant dishwasher. It's common for trucks to park on the side of the road, he said, though signs warn that it is illegal to park there from 9 p.m. to 6 a.m.

The impact of the collision awakened his family, Reyes said.

"I felt it. My whole family woke up," Reyes said. After the sound of the impact reverberated through his house, he went outside to see the accident, he said. "When I got outside the car was ... under the truck."

The car was going east on Suffolk Avenue, a residential street just north of the Long Island Rail Road.

The tractor-trailer, owned by PGN Transportation Inc., of Hickory, N.C., was operated by Charles Howard, 29, of Newton, N.C. The tractor-trailer was checked at the scene by officers from the Highway Patrol Bureau's Motor Carrier Safety Unit. The truck driver was issued 15 summonses for various violations, none of which contributed to the accident, police said.

The Ford was impounded for a safety check.

Initial evidence does not indicate that speed, alcohol or drugs played a part in the accident, police spokesman Tim Motz said.

Traffic was blocked off from Suffolk Avenue to Washington and Nimitz avenues for much of the morning.