Investigators released details of the fatal collision that killed 25-year-old Calera firefighter Christopher Roy.

Roy died Nov. 28 when the firetruck he was driving collided with a tractor-trailer at the intersection of the Interstate 65 South exit ramp and County Road 87.

Sgt. Tim Sartain of the Alabama State Troopers released details of the investigation, concluding that the tractor-trailer driver’s vision was obstructed by a dump truck.

The dump truck was in the lane to the left of the tractor trailer as both prepared to turn left onto County Road 87.

The firetruck was approaching from the right, with siren and lights activated as Roy responded to a fire call.

According to the investigation, the dump truck proceeded through the intersection as the light turned green. Since the tractor-trailer driver could not see the light, he proceeded after the dump truck, Sartain said.

The dump truck cleared the intersection, but the firetruck collided with the trailer portion of the tractor-trailer.

Sartain said Alabama law implicates both drivers in the collision.

Section 325a115 says that upon the approach of an emergency vehicle, other drivers shall yield the right of way and stop and remain clear until the vehicle has passed. Section b of the same law says this does not relieve the driver of the emergency vehicle of duty to drive safely.

&8220;It’s kind of like both parties have responsibility in this,&8221; Sartain said.

Sartain said he wasn’t sure if the dump truck driver or the tractor-trailer driver could hear or see the firetruck approaching.

&8220;Between the roar of those two vehicles it would be very difficult to hear or see,&8221; he said.

Last week, the dump truck driver came forward and talked to investigators. The driver continued driving away following the fatal collision