BOURNE, Mass. -- A woman was killed and three others were seriously injured Monday in a one-car crash on a rain-slicked road in Bourne, police said.

A 1984 Porsche 944 coupe, driven by Jonathan Muir, 21, of Falmouth, crashed into a tree on County Road in Pocasset early in Monday morning.

Cassandra Flynn, 21, of Bourne, who was sitting in the back seat was killed. Erica Pouler and Sonya D'Angelo, both 21, of Bourne, were passengers in the car. None of the four was wearing a seat belt, police said.

The Porsche "appeared to be traveling at a high rate of speed," said Bourne Sgt. Dennis Woodside.

"It was speed and wet pavement," Bourne Police Chief Earl Baldwin said. "I have been in the business for 35 years and the message never seems to get through. Speed and certain cars and people being 21 think they are bullet proof. Unfortunately, it's not the case."

Two of the surviving victims were taken to Falmouth Hospital. One was taken to Tobey Hospital in Wareham.

Pouler, who turned 21 the same day, and Muir suffered life-threatening injuries, according to police.

"At first we saw three people in the car. Then he opened a door and we saw another person. It was a nightmare. It was bad," witness Franco Raponi said.