A driver outside a Minneapolis Catholic school that was the site of a mass shooting on Wednesday morning said he stopped to help a man who was "running for his life."

Andrew Faust was driving to work when he "started hearing loud noises" and saw a man "frantically running" around 8:20 a.m.

"That kind of alerted me that something was wrong, and we heard probably about 15 to 20 gunshots in about 30 seconds," Faust said.

Faust invited the running man into his car.

"He said, 'Yes, yes, please.' He's like, 'Someone's shooting at me, someone's shooting at me,'" Faust said. "And so, we get in the car and we just ask him what's going on, and he said a man dressed in all black was firing shots." 

The man told him he didn't see anything other than what the shooter was wearing, and he hit the ground before getting back up, knowing he had to start running.

Faust went on to say he brought the runner to safety, but was told by the runner that the shooter was firing in the parking lot near the school. 

Faust said he called 911 and informed other passing drivers of the shooting. He saw "a fleet of police cars coming the other way and ambulances coming the other way." He added that police responded in seconds, saying it was comforting as someone who lives by the school, located near the Minneapolis-Richfield border.

Minneapolis Police Chief Brian O'Hara said the two students were killed, ages 8 and 10. Twenty-one others were hurt, 18 of whom are kids, and two of them are in critical condition. The three adults injured are all in their 80s.

"My heart goes to everybody who was affected by this. Obviously, it's just so tragic and so sad and so meaningless," Faust said. "I just, I hope people are OK."