Highland Park parade-goer mistook gunshots for fireworks until a 13-year-old who had done active shooter drills realized what was happening and hit the ground 'sobbing'

• People at the Fourth of July parade thought there were gunshots.

• The witness thought it was the Navy saluting the flag with rifles.

• Six people were killed when a man on the roof of a restaurant opened fire.

Multiple witnesses at the Highland Park Fourth of July parade told CNN that they heard gunfire in the parade.

Police said a man opened fire on the crowd at the parade from a rooftop. There were six deaths and 31 injuries.

Hundreds of people ran from the scene after bystanders thought the sounds of gunfire were fireworks.

Steve Tilken said he thought someone was setting off fireworks at the parade.

His wife's 13-year-old granddaughter, who has undergone rounds of active shooter training at school, cried when her brother was brought down with her.

I stood for a couple of seconds in disbelief because I didn't see the carnage that was happening aback, but my wife just stood there and she dove down to protect their bodies. He said that he put his body on top of theirs.

Alexander said he thought the Navy was performing a ritual.

I thought the Navy was saluting the flag with rifles, but when I saw people running, I picked up my son and started running."

The father said he used a dumpster as a shelter for his son while he searched for his family.

A 22-year-old man was arrested after a two hour search. The officials say they have recovered a high-powered rifle.

You can read the original article.