Within the first few months after the bombing, it is estimated by the Radiation Effects Research Foundation (a cooperative Japan-U.S. organization) that between 90,000 and 166,000 people died in Hiroshima, while another 60,000 to 80,000 died in Nagasaki. These deaths include those who died due to the force and excruciating heat of the explosions as well as deaths caused by acute radiation exposure.