A 2-year-old girl died Wednesday after her father allegedly left her in his car for about seven hours while working at home in Tsukuba, Ibaraki Prefecture, police said.

The father found his daughter, who was unconscious and not breathing, on the rear seat of his vehicle at around 3:20 p.m., and she was pronounced dead at a hospital, the police said.

According to the police, the 40-year-old man drove his 8-year-old daughter to an elementary school in Tsukuba at around 8 a.m., with the 2-year-old also in the car.

The man then returned to his home and worked there for a few hours. At around 3 p.m., he drove back to the school to pick up the elder daughter, and after parking at the elementary school he noticed his younger daughter still in the child seat in the back of the car, the police said.

The man told police that he was supposed to drop off the 2-year-old daughter at a nursery school in the morning but "forgot" to do so, according to investigators.

The temperature that day in Tsukuba reached 27.8 degrees Celsius shortly before noon, according to the Meteorological Agency.

The man has been working at home since May and was in charge of driving his daughters to and from school while his wife worked outside, police said.