The climax of "BlobFest" at the Colonial Theatre was a re-enactment of that scene, in which the audience runs out screaming and trying to escape The Blob, KYW-TV, Philadelphia reported. The day for the festival was chosen, of course, because it was Friday the 13th.
The low-budget movie about a pulsating alien life form that grows bigger and bigger by ingesting everything in its path featured Steven McQueen in his first lead role and helped make him into the star Steve McQueen.
One family made it to the festival from Alaska, although they also took in a family reunion in Toms River, N.J.
"This is what I wanted to do for my 60th," Diane Bongiovanni said.
Many attendees came in costume, like Susy Conrad, who wore a fetching hat fashioned from foil.
"The foil hat of course so the aliens can't suck out my brain, but I wanted to do it as a fashion statement at the same time," she told KYW.
The theater planned to show "The Blob" through the weekend.
"The Blob was made in our town and we're very proud of that," Mary Foote, who manages the theater, said.