Mastery charter schools were hit with a ‘system disruption’ to their IT network

Mastery Schools, Philadelphia’s largest charter school network, experienced a “system disruption” to its IT infrastructure Monday that took phones offline and limited email access, officials said.

While the network initially characterized the event as a hiccup that did not impact classroom instruction, a teacher disputed that account, saying the outage had upended plans in numerous classrooms that rely on internet connections and Chromebooks for lessons.

In a statement late Monday, Peter Lee, Mastery’s chief information officer, did not comment on the reason for the disruption.

On Tuesday, Mastery’s CEO, Joel D. Boyd, said the charter network had shut its systems down after noticing “suspicious activity attributed to an unauthorized external source.”

Mastery has engaged “experienced cybersecurity professionals” and contacted federal law enforcement, Boyd said. He said there was no indication of identity theft or fraud.

The charter network, which operates schools in Philadelphia and Camden, had not given a reason for the disruption Monday but had said it was “working with experts to address the issue and get the schools back online as quickly and securely as possible.” Families were able to contact schools through direct cell-phone lines, officials said.

A teacher at Mastery Hardy Williams in Southwest Philadelphia, who requested anonymity for fear of repercussions from administrators, said the school’s teachers were told by their principal before coming to school Monday morning that the internet was down.

An hour later, they were told to prepare for possible days of outages, the teacher said.

“It’s a bit ironic,” because Mastery just transitioned this year to a one-to-one system that has all students working on Chromebooks and requires all graded assignments to be turned in electronically, the teacher said.

While a number of teachers didn’t have lessons prepared on paper — “we get in trouble if things are not on the computer,” the teacher said — some did have written backup plans. Others improvised.

“Everyone got really creative, which was incredible to see,” the teacher said. But “you could feel the stress,” with the prospect of disruption continuing for days.