While many ran for cover amid the screaming and cries that filled the air after gunfire erupted at the Highland Park parade mass shooting, which killed seven and injured dozens, others jumped into action.
Dr. David Baum, who was at the parade and helped treat people injured in the shooting, said he saw several people shot.
"The bodies that I saw, it was not an image that anyone who's not a physician would have an easy time processing," Baum said.
He said those who died at the scene were quickly identified by paramedics due to "horrific" injures, which he compared to "wartimes."
Feeling out of the loop? We'll catch you up on the Chicago news you need to know. Sign up for the weekly Chicago Catch-Up newsletter here.
One couple said they thought the "pop, pop, pop" sounds heard at the parade were firecrackers, until they lasted longer than expected.
"Then we started hearing a louder shot - it sounded like a gun, but you don't wanna believe, you just think 'oh, maybe it's a bigger firecracker or something," the woman said.
The crowd then burst into panic, she said, and everyone began running as the shots continued. The woman said she dove under a concrete object with her dog and realized she had to pretend she was dead in case the gunman came by.
"I was trying to arrange myself like I was dead because I was looking all around and people were running and there was blood everywhere," she said.
However, she was suddenly met with a frantic man asking her to hold his 2 and a half year old daughter.
"So I put her underneath me and I put my arms around her and I said, 'don't worry, I'll keep you safe. I'll keep you safe,'" she described.
NBC 5 later learned the father gave the woman his daughter to run back and attend to his wife who had been shot. The wife is expected to recover and the toddler was reunited with her family.
Gabriella Martinez said many thought the gunshots were fireworks, but things quickly changed.
"We started hearing what we thought were fireworks in the beginning because we thought it would... I thought it was part of the parade so I told her like 'fireworks,' and then literally like one second (later) we all started getting into a panic mode," Martinez told NBC Chicago.
She noted that she saw a gunman on the rooftop of a nearby business aiming in her direction and ran with her daughter into another business on the street.
"I ran into the store and then we started running away from the doors and then like five minutes later I started like getting like into the reality that we were getting shot at, like I was like in total shock mode," she said.
At Bright Bowls, located at 777 Central Ave. in Highland Park, owners housed around 100 people fleeing from the parade in their basement for two hours.
"We were first running on adrenaline," Bright Bowls owner Lindsay Metlzer said. "Nothing was really going through our minds except 'we're all safe. Is there anyone else that need to be safe?'"
The children in the basement were seen coloring and singing in circles together, with little knowledge as to what had just happened along Central Avenue.
Sign up for our Breaking newsletter to get the most urgent news stories in your inbox.