At least four people have been killed at a hospital building in Tulsa, Oklahoma, on June 1, by a gunman, who also died from a self-inflicted gunshot wound, according to police. The shooting occurred a little before 5 p.m. local time on the campus of Saint Francis Hospital, Tulsa Deputy Police Chief Eric Dalgleish told reporters. Officers responded to the scene within three minutes and made contact with the gunman about five minutes later, he said.