"Pop" noises near 42nd and Walnut streets prompted a UPenn Alert on Sunday afternoon.

The alert was sent out at 12:41 p.m. after the Division of Public Safety received multiple phone calls about the noises near St. Mark's Square, Vice President for Public Safety Maureen Rush said. The alert was meant to keep people away from the area while Penn Police were still investigating and interviewing the callers, she added. An all-clear message was sent out at 12:59 p.m.

“A lot of times a car can backfire [and] that can sound exactly like a gunshot,” Rush said. Nothing at the scene led Penn Police to believe there was evidence of gun shots.

Earlier this year, another false gun scare occurred on 41st Street between Pine and Baltimore streets. The gunshot-like sounds actually came from a transformer that exploded, but a UPenn Alert was also issued during the investigation.

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