A 22-year-old man remained in critical condition on Tuesday after he was injured when a car smashed into a bus shelter in St. Paul this weekend.

Police are investigating whether Esteban Martin, of St. Paul, was struck by the car or by flying debris on Saturday, said Sgt. Mike Ernster, a St. Paul police spokesman.

A woman in the Metro Transit bus shelter in the Dayton’s Bluff area reported she heard glass shattering and was suddenly knocked down. She called 911. Paramedics also took her to Regions Hospital.

Police responded to Third and Earl streets at 4:43 a.m. Saturday. The driver, Darius Antwan Smith, and a passenger reported a tire had popped, which caused him to lose control of the Chevrolet Cruze, Ernster said.

Officers gave Smith a preliminary breath test, which indicated he had been drinking, and police arrested him on suspicion of criminal vehicle operation, according to Ernster. Police also obtained a search warrant to draw Smith’s blood for testing and the results are pending.

Smith, 38, of Minneapolis, was booked into the Ramsey County jail and released Monday. Police said their investigation is continuing.

Police found Martin unconscious on the ground near the heavily damaged bus shelter. He sustained a life-threatening head injury, Ernster said.

The 32-year-old woman who was knocked over in the bus shelter had a possible ankle injury and minor cuts from the glass. She was treated and released from the hospital.

Smith also had a cut to his hand from breaking glass and paramedics treated him at the scene, Ernster said.

Smith could not be reached for comment Tuesday.