City crews were expected to start work Sunday to fill a sinkhole near the mauka entrance of Kai­lua town.

The sinkhole, which formed at about 12:30 a.m. Friday morning near the corner of Hama­kua Drive and Kai­lua Road, was described as 20 feet long by 12 feet deep. What caused it had not been determined.

"It’s going to take some time," said Markus Owens, spokes­man for Hono­lulu’s Department of Environmental Services.

The inbound lane into Kai­lua was closed through the day.

Owens said workers would need to repair a wastewater pipe break in the sinkhole. The work included bypassing the sewage break with a temporary above-ground line connected through manholes.

The city hired a private contractor to repave the affected stretch of roadway. Work is to start Sunday.

In January an 8-by-8-foot sinkhole formed on Mako­hi­lani Street between Keehu­hiwa and Hoku­lii­lii streets in Mili­lani.