AMERICAN FORK — About 4,700 homes and businesses in American Fork were without power for 15 minutes Wednesday.

About 2:20 p.m., a device that works similarly to a circuit breaker opened when it sensed a disturbance, which caused a power line to de-energize, Rocky Mountain Power spokesman Jeff Hymas said.

Crews were unable to determine what type of disturbance caused the device to open but restored power after they determined the line to be safe, Hymas said.

The disturbance occurred at a power substation, he said.