PITTSBURGH (Sports Network) -- Pittsburgh Steelers quarterback Ben Roethlisberger is in serious, but stable condition at a Pittsburgh hospital after being involved in a motorcycle accident Monday morning.

Dr. Larry Jones, chief of trauma at Mercy Hospital in Pittsburgh, issued a statement Monday afternoon and said that Roethlisberger was "undergoing some surgery for injuries he received in this accident today.

"He is coherent, he's making sense, he knows what happened, he knows where he is. From that standpoint he is very stable."

The nature of Roethlisberger's injuries have yet to be revealed, but the Pittsburgh Post-Gazette reported that he suffered a broken jaw.

"On behalf of everyone within the Steelers organization, I want to express my concern for Ben Roethlisberger," said Steelers president Art Rooney in a statement. "I am sure Ben knows that we are praying for his complete recovery. So far, we have been encouraged by the early reports from the medical team at Mercy Hospital."

Witnesses told a local Pittsburgh television station that Roethlisberger's motorcycle collided with a car in downtown Pittsburgh and the quarterback flew over the handlebars and hit his head on the car's windshield.

Roethlisberger was apparently not wearing a helmet, which is not required for riders of motorcycles in the state of Pennsylvania.

Police are investigating the accident, which a local station said occurred at about 11:30 a.m. (ET) at the intersection of Second Avenue and the 10th Street Bridge in downtown Pittsburgh.

Reports added that a car, with Maine license plates, was traveling in the opposite direction of Roethlisberger's motorcycle and turned left. Roethlisberger was unable to stop and the motorcycle hit the passenger side door.

The 24-year-old Roethlisberger helped the Steelers to the Super Bowl title last year. He completed 62.7 percent of his passes for 2,385 yards with 17 touchdowns and nine interceptions last season, his second in the league.