CLARKSVILLE, Tenn. -- Authorities in Clarksville said a 15-year-old Northwest High School student was hit by a vehicle and critically injured Tuesday morning.

Video: Clarksville Teen Hit By Car, Severely Hurt

The incident happened at the corner of Purple Heart Parkway and Evans Road at about 6:45 a.m.

Clarksville-Montgomery County Schools spokeswoman Elise Shelton said the injured sophomore, Joshua Castle, was taken by helicopter to Vanderbilt University Medical Center.

Police Capt. Gary Perry said medics responded to the call and found the young man in the middle of the road with critical traumatic injuries.

School Principal Ed Stephens was also among the first to arrive after the crash.

"Well, it’s difficult to explain it children. How do I explain it to my teachers? How do I accept the ultimate reality myself?" he said. "We’re hanging in there."

Authorities do not think speed or alcohol was involved and don't think there will be any charges. Castle remained in very serious condition at Vanderbilt Hospital late Tuesday.

One of Castle’s classmates drove up at the scene.

"Me and my best friend were driving down the road when we saw the accident this morning," said Russ Allen. "It took a little bit for it to hit me that something like that could actually happen to somebody so good."

Allen said Castle loves the outdoors.

"He loved to hike. He loved to sit out in the woods. He loved to be real active. You know, he never wanted to sit around at the house and be lazy," he said.

Tragedy is no stranger to Northwest High School. Last year, basketball Coach Willard Ross was killed at a fireworks stand.