A woman was found dead Wednesday morning after a fire destroyed three buildings at a private welfare institute in Yorii, Saitama Prefecture, police said.

The fire broke out at the social welfare institute Kobo-no Sono (Gardens of Hope) at about 8:30 a.m. and razed three of its seven wooden structures, with a total floor space of some 490 sq. meters. The facility aids the rehabilitation of mentally disabled people.

The body of a 54-year-old woman was discovered in the bathroom of one of the burned buildings, where the fire is thought to have started.

Twenty-one people -- 16 residents and five staff -- were in the facility when the fire started. Police are investigating.