eleven people were reported injured in the blast. tepco and nisa announced that four tepco employees, three subcontractor employees, and four self-defence-force soldiers were injured. six military personnel from the ground self defense force's central nuclear biological chemical weapon defense unit, led by colonel shinji iwakuma, had just arrived outside the reactor to spray it with water and were exiting their vehicles when the explosion occurred. iwakuma later said that tepco had not informed them that there was a danger of a hydrogen explosion in the reactor, adding, "tokyo electric was desperate to stabilize (the plant), so i am not angry at them. if there is a possibility of an explosion, i would be reluctant to send my men there."