Multiple shots rang out on Birmingham’s busy First Avenue North at a reunion picnic for Woodlawn High School evening.

A woman was seriously injured, and multiple cars were damaged by the gunfire.

The shooting happened shortly after 7 p.m. in the 5600 block of First Avenue.

Officer Truman Fitzgerald said East Precinct Officers received a call of multiple shots fired.

The city’s Shot Spotter gunfire detection picked up one incident of three shots fired, and then a second burst with 10 shots fired.

Officers arrived to find about seven vehicles damaged by the gunfire.

A young woman then showed up a short time later at UAB Hospital with gunshot injuries. She told staff she was shot at Woodlawn High School.

The school has had reunion activities all week, culminating Saturday with a picnic and other festivities at the school.

Fitzgerald said two groups of people who were in attendance at the function got into an argument. The argument was between one person from each group.

One of those involved retrieved a gun from a vehicle and a gunfight ensued.

“The next thing you know, multiple guys are shooting at each other in a crowded parking lot,” Fitzgerald said.

“We know these two groups were already here participating in the Woodlawn function,” he said.

“We know somebody knows at least one person from those groups. If you turn that information into Crime Stoppers, you can receive up to a $5,000 cash reward.”

Fitzgerald said those in attendance are the detectives’ greatest resource and police are asking those witnesses to come forward.

“It’s a scary thought to think multiple guys were shooting at one another in a crowded parking lot,” he said. “This could have been horrible.”

Anyone with information is asked to call investigators at 205-254-1764 or Crime Stoppers at 205-254-7777.