A girl who was left unconscious for three years after being trapped under a bookshelf that toppled over in a secondhand book store here in 2009 has died.

The 13-year-old girl, Aina Suzuki, died at a medical facility in Sapporo on the afternoon of Sept. 18. Police plan to conduct an autopsy to determine the exact cause of her death.

Aina's 47-year-old father, Atsuhiro, visibly shocked, said his daughter's condition had suddenly worsened the previous day.

"She had remained in a critical situation, but I had believed that she would wake up someday. I can't believe she's died. My mind has gone blank," he said.

The accident occurred on Oct. 13, 2009, when three rows of wooden bookshelves, each standing about 210 centimeters tall, collapsed at the Daily Books store in Sapporo's Higashi Ward. Aina was hit in the chest by fallen books and subsequently fell unconscious, while her 17-year-old sister Airi suffered light injuries.

Airi said that immediately after the accident, when Aina was asked, "Can you breathe?" she replied, "No, I can't," and then her voice gradually grew fainter.