Three people died and another was listed in critically condition early Thursday after a fire, possibly caused by lightning, broke out in a house in Yamagata around midnight Wednesday, police and firefighters said.
The dead were identified as Mitsuo Suzuki, a 43-year-old farmer who owned the two-story wooden house, his oldest daughter, Hikaru, 9, a third-grader at an elementary school, and oldest son, Kazuhiro, 6, a first-grader, police said.
Suzuki's mother, Hiroe, 67, was in critical condition, they said, adding his wife, Chieko, 34, was in a Tokyo hospital.
The cause of the fire is under investigation, but police suspect lightning, noting the roof of the partially destroyed house, located in a rural area about 3 km northwest of JR Yamagata Station, was badly burned and a neighbor heard a thud before the fire broke out.
A thunderstorm was hitting the area when the fire broke out.