Power went out for more than half of Hawaii island Monday morning as rain from remnants of Tropical Storm Barbara drenched the island.

The widespread power outages caused an array of traffic signals to fail, according to police and civil defense officials.

A spokeswoman for Hawaii Electric Light Co. said power to about 51,000 customers on the island was interrupted shortly before 10:45 a.m., but service was restored to all but about 1,600 customers in Hawaiian Ocean View Estates by about 12:15 p.m.

Service to the remaining customers was restored by about 1:30 p.m., according to HELCO spokeswoman Kristen Okinaka. HELCO has about 86,000 customers on the island.

Hawaii island police warned at about 11:30 a.m. that “island wide traffic lights (were) malfunctioning,” and asked motorists to drive with care. Four- way intersections are treated as four-way stops when the signal lights fail, authorities said.

Police said at about 12:40 p.m. that most malfunctioning traffic lights had been restored.

Okinaka said the outage was traced to faults on two transmission lines along the Hamakua Coast that disconnected independent power producer Hamakua Energy from the electric grid, causing a sudden loss of power generation.

The cause of the line faults is still under investigation, but they were likely caused by wind gusts blowing tree debris onto lines, Okinaka said in a written statement.

Hawaii County Civil Defense officials said residents called to report power out in the isolated Hawaiian Ocean View Estates area of Kau as well as in more densely populated areas such as Waimea. Power was also reported to be out in Honomu, Keaukaha and Waiakea in the Hilo area.

Okinaka said there were reports of some customers losing power in Kona as well.

HELCO warned in a written statement that steady rain and flooding can uproot trees and break branches that can fall on power lines and snap utility poles. The public should always assume downed power lines are energized and dangerous, and should stay at least 30 feet away, according to the utility.