O’Hare International Airport experienced multiple power failures over the weekend after heavy rain possibly knocked down power lines.

Two “brief” power surges happened June 29 and 30, and affected the airport’s phone systems, radios and internet, the Chicago Department of Aviation said in a statement.

The power outage did not affect the airfield or security operations, the CDA said.

“ComEd dispatched crews to investigate the situation and got the systems back on line after heavy rain and possible downed power lines,” the CDA said in its statement.

Workers with ComEd were alerted to one of the outages at 6:30 a.m. Sunday, ComEd spokesman John Shoen said.

The outage was limited to the CDA’s communication center, and power was restored 45 minutes later, Shoen said.

The cause of the outage was a “cable fault,” although it was unclear what caused that, Shoen said.

“It could’ve been anything,” Shoen said. “There was what we call a ‘lockout,’ which is similar to a fuse breaking in a home. We were alerted to it, and we went out and fixed it.”

O’Hare hasn’t experienced a major power outage recently — like Atlanta’s International Airport’s 2017 outage that shut down the airport for 11 hours — but O’Hare has recorded minor events.

In 2013, a power outage at O’Hare darkened lights on four arrival runways for about 40 minutes. In 2011, power was lost at four of O’Hare’s terminals for about 20 minutes, shutting down screening operations.

In the summer of 2004, an explosion during maintenance work to the airport’s electrical system injured two workers and cut power to two terminals for four hours. The outage did not affect air traffic controllers, but flights were delayed because power was cut to security checkpoints, forcing security to manually check passengers and baggage. The temperature in the terminals was described like a “sauna.”

Shoen said ComEd has done a lot of work to create redundancies to limit future outages, although it’s not always faultless.

“Sometimes things happen on the cables,” Shoen said. “But we’ve got equipment in place nearby to take care of that.”