HONOLULU -- Power was restored to nearly all of Hawaiian Electric Co. customers on Oahu at about midnight on Sunday, according to a representative.

HECO experienced an island-wide power failure shortly after Sunday's earthquake.

The generators went offline after the quake because of the way the system is set up, according to HECO spokesman Jose Dizon. When the system detects major instability it starts to shut down generators, he said.

The generators were able to accommodate the load of power use at about midnight, when there was less of a tax on the system, Dizon said. HECO brought more generators online by the time many residents began waking up, he said.

Pockets of outages remain throughout the island. These are isolated areas that crews need to deal with on site, according to Dizon.

Many of the areas had blown fuses in the transformers, he said. Crews were dispatched to replace fuses and work on other issues in the outage areas.

There was no time frame for when the repairs would be complete.