HIGHLAND PARK, Ill.  — Mark Heymann was marching in the Highland Park parade when shots rang.

“It’s strange because people were supposed to be in this park on the Fourth after the parade and to have someone here for a completely different reason is kind of surreal,” Heymann said.

Speaking with WGN News on Thursday, Heymann says he was playing his clarinet with the high school band as the school invited alumni back to partake in the festivities. Band members and parade-goers would soon run for cover.

“We were about 3/4 of the way through the parade route and we heard what sounded like gunshots or fireworks or something,” Heymann said. “We kept marching and playing for about 20 or 30 seconds before we realized what was going on.”

Widely shared cellphone video captures the band’s rush away from the scene.

All band members made it safely to a nearby school bus.

In the days since the mass shooting that killed seven people and wounded dozens, many have mourned, grown angry and expressed their intention to take action, calling on the ban of assault weapons.

Heymann says in times of tragedy, people must unite to lift one another.

“Events like these, people come together,” Heymann said. “They find strength in being with one another and the community.”