Trouble shooters from the Hawaiian Electric Co. are trying to determine what caused a power outage in the general Makiki and MCCully areas for about 20 minutes this morning.

HECO spokesman Darren Pai said the power went out about 8:10 a.m., but had been restored by 8:35.

Police reported signal lights were out at the intersections of South King Street and Kalakaua Avenue, as well as Keeaumoku Street and Wilder Avenue.

No estimates were immediately available on the number of customers affected by the outage.