A teacher at a school for children with autism died a hero in Bourbonnais, Illinois on Monday, pushing one of his students out of the way of an oncoming bus.

Thomas "Jim" Dunn, Jr. had been working as a mentor to the 19-year-old male student for over a year. On Monday, like every school day, the two crossed the street from the Camelot Therapeutic Day School to a gas station to grab a soft drink.

On their way back from the gas station, a River Valley Metro Mass Transit bus turned onto the road they were crossing. The student was in its path, until Dunn leapt out and shoved him out of the way, according to initial witness statements. Dunn was struck, rushed to the hospital, and pronounced dead that afternoon.

"He was an angel sent down from heaven, that's all I can say," the student's mother told the Chicago Tribune.

Interim Bourbonnais Police Chief Greg Kunce had fond remembrances of Dunn as well, from Dunn's time as an auxiliary police officer. "Knowing Jim Dunn, it wouldn't be surprising had he done that," Kunce told ABC-7. "He's a true hero if in fact it's determined that he pushed that child out of the way. That's a selfless act that he would have done."

Dunn was a single father of two: Ian, his 15-year-old son, and Brenna, his daughter, who turns 11 years old today. The kids are living with their uncle, town attorney Patrick Dunn. Dunn worked tirelessly with his son Ian to help him overcome ADHD and dyslexia.

According to the Tribune, he was a history buff and a Star Trek fan, as well as a dog lover who belonged to a rescue organization for Labrador retrievers.

WGN reports that the school is moving to rename its playground after Dunn.

Watch ABC's coverage of the tragic accident: