Philadelphia - (NBC) - A Facebook invitation "30th Street Station Freeze" promising more than 1,300 people to meet at 30th Street Station 6:30 p.m. Thursday to simultaneously freeze in place for three full minutes seemed to live up to expectations.
An April Fool's joke? No, it was for real outside of the amount of people which seemed more in the hundreds than 1,300.
The "flash mobbers" froze in place when the clock struck 6:30 just like they said they would.
The "real" flash mob was sponsored by a local improv group - Stealthy Elephant and the Drexel Flash Mob, reports the Daily News.
The inspiration for the "freeze" came from the famous "Frozen Grand Central" performed by New York-based Improv Everywhere, the organizers of the Philly event said on the Facebook invitation.
"The people involved loved it, and the strangers who saw them all got a great laugh," the page said about "Frozen Grand Central."
The event was classified as a "real" or "genuine" flash mob in light of the past few months of sudden, violent teen gatherings in different parts of Philadelphia that were branded by police with the same name.
Before that, the term "flash mob" simply referred to a large group of people gathering in public en masse to briefly perform an artistic stunt, like dancing, singing, standing like statues. "Improv Everywhere" has become famous for its purposely-awkward flash mob performances in large public places.
One of the Facebook page's administrators addressed the city's recent perception of flash mobs on the page: "As long as everyone stays nonviolent, we can show the world that Philly can still have fun," the organizer wrote. "Other flash mobs have recently given us a bad name - let's change that."