An investigation is underway after a collision Monday at a Phoenix transit yard left one man dead and two others injured, police said.

Officers were called to the city yard near 79^th Avenue and Van Buren Street just after 5 a.m. Oct. 7 and found a man on the ground with signs of trauma, according to a release from the Phoenix Police Department.

Two other men were found inside a shuttle bus with non-life-threatening injuries. Fire department personnel treated the three men who are employed by the city’s contracted transit provider, police said.

The two men found in the bus were taken to a hospital for treatment. The other man, identified as 59-year-old George Meletis, died from his injuries at the scene. 

Preliminary information suggests the driver of the bus, occupied by two of the men, took his foot off the brake, and “for unknown reasons, the shuttle bus accelerated forward causing the shuttle bus to collide with a parked car and run over Meletis," the release stated.

The  bus continued to accelerate and collided with a parked standard size bus before stopping. The other bus was unoccupied, police said, adding a charging decision will be made once the investigation is complete.