Police say a man struck and killed on Highway 401 Tuesday morning got out of his vehicle and crossed live lanes of traffic after a tire came flying off of his car.

It happened in the eastbound collector lanes of the highway near Keele Street shortly after 3:30 a.m.

According to OPP Sgt. Kerry Schmidt, the driver of a PT cruiser entered the highway near Islington Avenue and began to travel down the eastbound lanes with what appeared to be a flat tire.

At one point, the tire came flying off of the vehicle and the man continued driving on the rim before coming to rest on the left shoulder near Highway 400.

"At that point, apparently the driver exited his vehicle, either to assess the damage… we are not sure exactly what he was doing, to try to find help of some sort," Schmidt said.

"A few moments later, the driver entered the lanes of the highway and was subsequently struck by several vehicles."

The man, who is believed to be a 31-year-old Toronto resident, was pronounced dead at the scene.

Schmidt said police believe that the man was struck by at least five vehicles.

OPP's collision reconstruction team attended the scene on Tuesday morning and the investigation is ongoing.

Schmidt said police are investigating if the deceased was impaired at the time of the collision.

"We’ll have to wait for the coroner’s office to determine exactly what level of impairment, if any, was involved in this situation, but obviously that is going to be part of our investigation to determine whether or not this driver was impaired," he added.

Investigators have not yet released the name of the deceased.

"We are still working on notifying next-of-kin," he said.

"That will be taking place today as we continue to investigate."

Police are asking for any possible witnesses to the crash to contact investigators.

Highway 401 eastbound collector lanes were closed from Highway 400 to Jane Street and the ramps from southbound Highway 400 and Black Creek Drive were also closed to eastbound Highway 401 following the incident. All lanes have since reopened.

Schmidt said drivers should not exit their vehicles if experiencing car trouble on the highway.

"We don’t want people getting out of the vehicles really at any time and if they do have to get out of their vehicles, they need to assess the situation and determine where they are going and if they can do it safely," he said.

"Really just stay in your vehicle and call 911 and we will get emergency responders, MTO road maintenance crews or OPP to accompany and assist and provide blockage and protection for that person until we can get the vehicle removed."