A 31-year-old Lewiston man died Tuesday after falling off a trash collection truck owned by Pine Tree Waste.

Lewiston police Lt. Mike McGonagle said the cause of Mark Ehrenwald’s death remains under investigation, but police have not ruled out the possibility that he suffered some type of medical problem before falling at St. Jerome and Gina streets.

“The truck was not moving at the time, so speed was not an issue,” McGonagle said.

McGonagle said Ehrenwald’s partner, who was driving the truck, looked in his rearview mirror and saw Ehrenwald lying on the ground.

“Witnesses said he fell off the truck, but we’re still not sure what happened,” McGonagle said.

An ambulance crew tried to resuscitate Ehrenwald, who died at the scene.

The state Medical Examiner’s Office is scheduled to conduct an autopsy. Federal investigators from the Occupational Safety and Health Administration also responded.