A large sinkhole appeared overnight following heavy rain on Kanapuu Drive in Kailua Bluffs.

A portion of Kanapuu Drive near the Kahako Street intersection remained closed, as well as adjacent sidewalks, as crews Wednesday inspected the sinkhole on the shoulder of the road. The sinkhole, at least 15 feet across, also collapsed part of the sidewalk.

“What we discovered is a sinkhole, quite deep, anywhere from 12 to 15 feet deep,” said Robert Kroning, director of the city’s Department of Design and Construction. “We sent some engineers down the inlet side. They walked in and learned that there has been a collapse in that drain pipe — it’s a drain pipe that we’re talking about, corrugated, metal pipe, 12-foot diameter.”

Kroning said the city didn’t yet know how the collapse happened, but that it probably developed over many years or decades of slow corrosion. Engineers were not able to get too close to the collapsed pipe area due to safety reasons, he said.

“We’re in the process of hiring a company to come out there and do a much more detailed investigation for the repair of that site,” he said. “We’re going to get a contractor out there as fast as we can.”

Kroning said he didn’t know exactly how long repairs would take. If all goes well, and the fix involves a pipe replacement, he said it could take anywhere from one to four months.

“We do believe it’s very localized,” he said. “It’s just in that spot.”

Fortunately, residents above the closed off area of Kanapuu Drive have another outlet to enter and exit via Kalanianaole Highway. The affected portion of the drive will remain closed until repairs are made. Officials cautioned the public to keep clear of the taped-off area.