A 4-year-old girl fell to her death from the 18th floor of a high-rise apartment late Monday in the city of Kurume, Fukuoka Prefecture, police have said.

Mion Ezaki was found on the roof of a store located on the first floor of the building after authorities received an emergency call from the apartment at around 8:45 p.m., police and rescue workers said.

The unconscious girl was taken to a hospital and later pronounced dead.

Police said they are investigating the case, believing the girl may have fallen by accident from the balcony of her family's apartment.

According to the police, Mion and a younger sibling remained in the apartment while their father was out to pick up their mother.