Hawaii transportation officials were assessing an unstable slope above a busy highway on Oahu Tuesday after a landslide on the roadway sent three people to the hospital.

The Pali Highway, which connects Honolulu and the east side of the island over a steep mountain range, was completely closed Tuesday. Portions of it will remain shut down all week after multiple landslides covered the roadway in two spots on Monday, Hawaii Department of Transportation spokesman Tim Sakahara said.

A small landslide closed one lane of the highway Monday morning, but Sakahara said rocks and debris were cleared and the lane was quickly reopened. Several hours later, another larger landslide hit in the same spot, covering the roadway and closing all lanes heading away from Honolulu. There were no injuries or vehicles hit.

The Honolulu-bound lanes remained open. But about an hour later, another landslide struck nearby, sending huge rocks and debris crashing onto the open lanes where a pickup truck was passing into a tunnel.

A 40-year-old Kaneohe woman who was riding in the bed of the truck was injured, Honolulu Emergency Medical Services spokeswoman Shayne Enright said. The woman sustained non-life threatening injuries and was taken to the hospital in serious condition.

Two girls, ages 2 and 9, were also in the truck and taken to the hospital but were not injured, Enright said.

The Honolulu-bound lanes of the highway, where the vehicle was hit, will remain closed until at least Monday, Sakahara said. He said there are several large boulders, some as big as a vehicle, that are still at risk of falling. Crews will need to secure the hillside before clearing debris on the road and reopening the highway.

Pieces of concrete from Old Pali Road, the original route from Honolulu to the windward side of Oahu, also came down with the slide. Officials said in a statement that the road had significant cracks and damage that need to be secured.

In August, a landslide covered the same area of the Honolulu-bound lanes of the highway during the morning rush-hour commute. Falling rocks damaged four vehicles during that landslide, but no one was injured.

The highway was closed in both directions as officials inspected the hillside. But the road was cleared and reopened before the afternoon commute.