Fearing possible gunshots, it took only the collapse of a police barrier at a politically charged New York celebrity music show Saturday to send thousands of spectators fleeing in panic.

About 60,000 people had filled the park's Great Lawn for the eight-hour Global Citizen Festival. They listened to big-name personalities from Democratic New York Gov. Andrew Cuomo and Republican Sen. Jeff Flake to Janet Jackson and John Legend who all urged spectators to get involved in the nation's troubled politics.

Suddenly, just before 8 p.m., the police barrier that was meant to keep the crowd in check toppled over, releasing a clanging sound that terrified many spectators.

Authorities quickly took the stage, assuring the crowd they were safe.

Burning social justice issues dominated the eight-hour event that had started on a sunny afternoon. Also scheduled were Cardi B, The Weeknd and other pop stars.

Some speakers asked the audience to call their Congress members to react to this week's Senate hearings for Supreme Court nominee Brett Kavanaugh.

"We want equal justice and a full investigation for the Supreme Court nominee, not investigations of limited time, not investigations of limited scope," Cuomo said. "And it means before you put a person on the Supreme Court to administer justice, we want to make sure justice is done."

In a video clip, former first lady Michelle Obama urged people to register to vote in the Nov. 6 midterm elections.

Speaking outside the show, Sen. Christopher Coons, a Delaware Democrat, called Flake "the real hero" after Friday's testimony that led the Arizona Republican to demand an FBI investigation into alleged sexual abuse accusations against Kavanaugh.

During a break in the Senate session on Friday, Coons said Saturday in New York, Flake's "first comment to me when we went sort of backstage in the anteroom was, this is tearing this country apart, and I deeply respect Jeff for standing up to a ton of pressure to demand a one-week pause and an expanded FBI background check."