A Gray-New Gloucester Middle School student was seriously injured Tuesday after being hit by a tractor-trailer truck while getting off the bus, according to police.

Emergency personnel responded shortly before 2:30 p.m. on Lewiston Road (Route 100) in Gray, not far from Spring Meadows Golf Club, and found a semi-conscious 13-year-old boy who was hit by a commercial truck while crossing the road, the Cumberland County Sheriff’s Office said.

The teen was taken by ambulance with a parent to Maine Medical Center in Portland.

Craig King, superintendent for MSAD 15, said the bus carrying middle and high school students had pulled over to let the student off.

The tractor-trailer truck, owned by Bard Trucking of Farmington, was operated by Jeffrey Lane, 49, of Farmington, according to the sheriff’s office, which is investigating the crash.

The school bus was driven by Joyce Hamilton, 62, of New Gloucester. Its lights were on and its stop arm was activated at the time of the crash, the sheriff’s office said.

The other students on the bus were checked out by emergency personnel at the scene and then returned to the school where their parents could pick them up and where counselors were made available, King said. He did not identify the student.