SAPPORO (Kyodo) Large bookshelves fell on three people and knocked them to the floor Tuesday at a bookstore in Sapporo, leaving a girl unconscious, police said.

Aina Suzuki, 10, was listed in serious condition at a hospital in the evening after she was hit by the falling bookshelves. They also hit her sister, Airi, 14, and a 19-year-old male employee at the Daily Books store in Higashi Ward at around 3:40 p.m.

"I saw a girl walk out of the mess by herself, and then another girl was moved out on a stretcher," said a person who saw the rescue scene.

According to the police, three large shelves, each standing 2.1 meters high and made of two-deck sections, fell in succession. The cause was under investigation. The sisters were trapped between a wall and the shelve closest to the wall.

The older girl sustained a minor injury to her head, while the store employee was unhurt, the police said.

The upper and lower decks of the shelves were not fixed to each other, investigators said. They launched a probe into the store operator on suspicion of professional negligence resulting in injuries.

Daily Books trades in secondhand "manga" comic books and used video games. Its main customers are children.

According to a group of junior high school boys who frequent the store, it had several bookshelves lined up in a tight space and people could barely walk between them.