CARY — A squirrel that got into a Progress Energy substation and came in contact with live wires caused an outage that affected more than 11,000 customers in Cary for almost an hour and sent police to direct traffic and post temporary stop signs at numerous intersections where signals were darkened.

A Progress Energy spokesman said the incident happened about 9:30 a.m.

By 10:20, the number of customers affected was down to 4,560, the company reported. And the Town of Cary said its traffic lights were functioning again.

Automatic safety systems tripped when the squirrel came in contact with the power, Progress said.

A total of 15 incidents showed on the company’s system, the spokesman said, and workers had to determine if those were anything that required repairs before they could turn electricity back on for all customers.