The city shut down the Ewa vehicular entrance to Ala Moana Regional Park at 4:15 p.m. Tuesday due to a sinkhole that’s undermined about 4 feet of road under Ala Moana Park Drive.

Only a small hole is visible on the surface of the pavement, but officials said the hole is larger underground.

Vehicles must enter and exit the park only via the Diamond Head entrance, across from Atkinson Drive, until further notice, city officials said.

Bicycles and pedestrians may still enter through all pedestrian entrances.

The city is giving no timetable for reopening the entrance, across from Kamakee Street.

Officials are trying to figure out what caused the sinkhole and how to fix it.

Barricades and traffic cones will surround the area in the meantime.