A witness to Monday's July 4th parade shooting says he thought the first shots fired were a military salute before realizing the situation and running.

The witness, identified only as Alexander, attended the parade with his son, according to ABC 7 Chicago. Robert Crimo III, 22, allegedly opened fire soon after the procession began.

"I thought it was the [U.S.] Navy saluting the flag with rifles, but then I saw people running, I picked up my son and started running. I ran to one of the buildings, I tried to break glass into get in with my son and I couldn't break it," Alexander said. "It was horrible. When I went back there were a few people shot on the ground... There was no target... it was shooting whoever."

"You're not safe anymore, you're not going wanna take your kids to a large gathering. And you're always going to have that. Like when you get in a car accident, traumatic," he added.

SUSPECT ARRESTED IN ILLINOIS FOURTH OF JULY PARADE SHOOTING THAT KILLED 6 PEOPLE

Highland Park, Illinois officer

An officer holds up police tape at the scene of a mass shooting at the Fourth of July parade in Highland Park, a Chicago suburb, on Monday, July 4, 2022. (AP Photo/Nam Y. Huh)

Police officers in Highland Park

Law enforcement search after a mass shooting at the Fourth of July parade in Highland Park on Monday, July 4. (AP/Nam Y. Huh)

Crimo allegedly killed six people and injured 30 others in the attack. He reportedly set up on a rooftop overlooking the parade route.

Images show lawn chairs and strollers abandoned along the street as parade-goers fled the scene.

ILLINOIS 4TH OF JULY PARADE SHOOTING LEAVES 6 DEAD, MORE THAN 30 INJURED; SUSPECT ARRESTED

Crimo's uncle, Paul Crimo, expressed his deep sympathies for the victims, but said he was shocked that his nephew is the suspect.

"There were no signs that I saw that would make him do this," Paul Crimo told Fox 32. "If I did see signs, I would've said something."

Paul added that Crimo is "a real quiet kid."

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"He keeps everything to himself, and he doesn't express himself," he explained. "So he just sits down on his computer. There's no interaction between me and him."