A 102-year-old woman in a wheelchair was struck from behind and killed by a delivery truck in Hidaka, Hokkaido, police said.
Yoshie Tabata, who lived near the scene, was not killed immediately but died later from the Tuesday afternoon accident, police said, adding her caretaker, Chieko Ueshima, 52, sustained head injuries.
Police arrested truck driver Masaru Abe, 44, at the scene on suspicion of negligence resulting in injuries and later upgraded the charge to negligence resulting in death and injuries.
Abe told police he was not watching the road carefully when the accident took place, according to investigators.
Tabata was the oldest family member in attendance at a government-sponsored memorial service for the war dead in Tokyo last August.