CHELSEA, Mass. (AP) – A Toyota Camry driving the wrong way crashed into a vehicle Monday just north of the Tobin Bridge, killing the car’s driver and an off-duty police officer, according to the Suffolk County District Attorney’s office.

Authorities would not release the victims’ names Monday night, but the Camry driver was described as a 50-year-old Nashua, N.H., resident and the other victim, driving a Honda Accord, was a Milton police officer.

“Our thoughts and prayers go out to the victims’ families and to the members of the Milton Police Department,” District Attorney Daniel Conley said in a statement.

The Camry was driving south on Route 1, when it hit a car, then flipped around and began driving north in the southbound lanes. It hit the Accord head on just south of Fifth Street.

The drivers in the Camry and the Accord were taken to Massachusetts General Hospital, where they were pronounced dead.

A passenger in the Honda, Ann Condon, 50, was taken to the hospital with serious injuries. She was a civilian employee of the Milton police department, officials said.

State police received numerous 911 calls reporting an erratic driver minutes before the accident.

The cause of the crash remained under investigation Monday night. Police would not speculate on why the Camry’s driver tried to leave the scene of the first crash.

Route 1 was closed for more than 3 hours following the crash, which occurred just before rush hour.

“The facts, the circumstances and the evidence will be reviewed carefully and meticulously throughout the night and into the days and weeks to come,” Conley said.