No one was injured Monday when an SUV operated by a 72-year-old woman crashed through the wall of the Cape Elizabeth Swap Shop.

Investigators were still trying to determine what caused the crash, Cape Elizabeth police Detective Ben Davis said. Drugs and alcohol have been ruled out, he said, and the woman’s name was not released.

The vehicle, which was towed from the scene as a precautionary measure, went through an exterior wall causing extensive damage to the building. The crash was reported around 2:30 p.m.

Beth Cary of Cape Elizabeth, who volunteers at the swap shop, was inside the building when the vehicle smashed through the wall knocking over a shelf loaded with hardcover books. Those books were sent flying before landing on glassware that shattered. The sound of the vehicle striking the building sounded like a bomb going off, she said.

“It startled everyone. There was this avalanche of books and crashing glass,” said Cary, who was not hurt. “We’re just very grateful that no one was injured.”

The town-owned swap shop opened in 1996, a joint project of the Cape Elizabeth Public Works Department and the town’s Recycling Committee.

It was designed to divert usable goods and materials from the trash stream. The swap shop accepts items such as toys, sporting goods, curtains, dishes, working electronic appliances, yard tools, kitchenware, books and magazines.

The swap shop building is located in the town recycling center on Dennison Drive.