Highland Park parade shooting survivors describe seeing alleged gunman on roof during parade

HIGHLAND PARK, Ill. -- As Abby Brosio stood with her father-in-law watching the Fourth of July parade in Highland Park on Monday morning, a hail of bullets began to fly from atop the building directly across the street.

"I remember looking around to try to figure out where the sound was coming from," Brosio told "Good Morning America" on Tuesday morning. "And I, in fact, looked up at the neighboring business across the street and saw the shooter on the roof, and I just screamed that it was a shooter."

WATCH: Video captures Highland Park parade-goers scrambling to safety

Video captured Highland Park parade-goers scrambling to safety.

She said she saw "long hair and a gun." As she turned to pull her 1-year-old daughter and 3-year-old son into Gearhead Outfitters, a store managed by her husband, Tony, she was grazed by a bullet, she said.

Her father-in-law was shot in the leg, she said.

MORE: Grandfather, lifelong synagogue member among parade shooting victims

Highland Park parade shooting victims range in age from 8 to 85, as family said Nicholas Toledo and Jacki Sundheim were among those killed.

Six people were killed and 31 others were injured in Monday's mass shooting in Highland Park, a suburb north of Chicago, according to officials. Police said on Monday they took into custody a 22-year-old person of interest, Robert "Bobby" Crimo III, in connection with the incident.

Tony Brosio was inside Gearhead Outfitters as the shooting began. As parade spectators rushed the store, looking to take cover, he helped coordinate. Video from inside the store shows crowds running inside. Some stumble, others glance behind them.

"We were just trying to get as many people as we possibly could inside," he told "GMA" on Tuesday. "Like I said, it was just instinct."

WATCH: Video captures moment police take person of interest into custody

Video shows a person of interest in the Highland Park parade shooting being placed into custody after a brief chase.

Both the Brosios had the feeling that it "could never happen" to them that they'd be in an active shooting situation, he said.

"You always have that, 'It could never happen here,'" he said. "It just did."

"It was like a dream. All I could say to myself was, 'This isn't real,'" Abby said.

As Abby and her father-in-law reached the safety of Gearhead Outfitters, she realized that they'd both been hit by bullets, she said. Both were taken to a local hospital and later released, she said.