A 37-year-old Waipio school librarian was sitting at her desk just before noon Thursday when a car slammed through the wooden wall of the library and computer lab, seriously injuring her and the 73-year-old female driver.

Both women were in stable condition, an Emergency Medical Services official said.

The crash sounded like an explosion, prompting Phebe Sumida, head administrator at Pearl Harbor Christian Academy, to issue an alert until the source of the noise became apparent.

"We thought we were under attack," Sumida said of the 208-student school. "We thought a bomb had exploded."

The phone lines went down, so they used cellphones to call 911.

The school’s younger children were immediately evacuated to the church sanctuary and shown a DVD to keep them occupied while fourth- to eighth-graders remained in the cafeteria for lunch. Kindergarten and preschool students were in a separate building a safe distance away, Sumida said.

The driver was headed north in a traffic lane in the parking lot but, instead of stopping or turning, went straight into the building. Along the way, the car jumped the curb, crossed a sidewalk and plowed through wooden pillars, a metal barrier and a metal bench, Sumida said.

Police said they saw no skid marks.

"By the grace of God, there were no kids in front of the office, no kids in the hallways, no kids in the library at all," Sumida said. "Amazingly, our computer lab teacher had to drop off his wife’s car … so he wasn’t in there when he normally would be in there."

She added, "A lot of our children were shaken that the librarian was injured."

The school and church, at 94-1044 Waipio Uka St., share the parking lot with a shopping mall where Big City Diner Waipio is located.

The crash made an enormous hole that Sumida described as the size of a "garage door," in the wall of the library and adjoining computer lab. The crash wiped out much of the library’s book collection, 26 computers, a projector and a 60-inch interactive white board.

Sumida said the school secretary saw that the driver "didn’t slow down at all and just went straight through the building."

The driver’s fiance told a school staffer that she called him to say she must have "blacked out or something," Sumida said.

The driver was taken by ambulance to Kaiser Permanente Moanalua Medical Center, and the librarian to the Queen’s Medical Center.

"We prayed for the librarian," Sumida said. "We prayed for the woman who went into the building."

Members of the affiliated Calvary Chapel Pearl Harbor include a contractor and electrician who shored up the building and put a temporary patch over the hole.

School staff members picked through the debris to salvage usable books.

Parents of all students were notified of the incident. The school, for grades one through eight, was shut down and will remain closed today.