The mystery of what caused Monday’s power outage that cut electricity to more than 7,000 Westar Energy customers in Lawrence has been solved.

Well, sort of.

Nick Bundy, Westar spokesman, said the cause will officially be classified as “equipment failure,” though it’s possible that storms in the area led to the failure.

“We can’t prove that lightning or the storms was the cause,” he said.

Bundy said it’s common that such equipment failures can’t be definitively linked to bad weather, and 39 percent of all Westar outages are blamed on equipment failures.

Monday’s outage, which affected most of downtown Lawrence, began around 9:30 a.m. and lasted until about 10:45 a.m. A second outage at 12:30 p.m., lasting about 20 minutes Monday, was caused by a fallen tree and affected about 1,700 customers in east-central Lawrence, Bundy said.