As Philadelphians settled in bars or on their couches at home to watch the U.S. women take on the Netherlands in the World Cup soccer final Sunday morning, an adrenalin rush of a very different sort played out on Thomas Jefferson University’s East Falls campus.

It was triggered by an alert that popped up on the cell phones of students, faculty and university employees about 10:15: “There’s an active shooter on the East Falls campus. Follow emergency procedures. Run. Hide. Act.”

About 20 minutes later came the “ALL CLEAR.”

“Please disregard the 10:15 message re: active shooter. There is no immediate danger to campus,” the text went on to say.

It was followed shortly before noon by a statement that the university issued on social media, attributing the false alert to "a resolvable system error.”

“There was no active shooter and we apologize for the error. We are taking further action to ensure this does not happen again,” the statement said in part.

Given that the alert came on a Sunday morning during a summer holiday, there were “very few students” on campus, said university spokeswoman Angela Showell.

Because of widespread power outages from Saturday night storms, the university was testing its JeffAlert system Sunday when the active shooter alert erroneously went out, Showell said. Campus security and Philadelphia Police responded, conducting a thorough check before the message declaring the campus free of danger was issued, she said. Monitoring and testing were to continue throughout Sunday to ensure that everything was in working order when summer classes and other campus activities resumed Monday.

“The good news is the system works,” said Showell, who said she was not prepared to provide specifics on why it had sent out the wrong message, however.

She did not catch one bit of the World Cup final, during which the American women secured a second-consecutive championship win.

“I was kind of tied up with this, making sure it was in fact an error and not an actual active shooter — thank goodness,” Showell said.