A doctor was killed today at Christus St. Joseph Hospital when an elevator malfunctioned, decapitating him, authorities said.

Hitoshi Nikaidoh, 35, of Dallas, a surgical resident at the hospital at 1919 La Branch, was stepping onto a second-floor elevator in the main building around 9:30 a.m. when the doors closed, pinning his shoulders, said Harold Jordan, an investigator with the Harris County Medical Examiner's Office. The elevator car then moved upward, severing the doctor's head, Jordan said.

A woman who also works at the hospital was on the elevator at the time and witnessed the accident, police said. Because of the malfunction, she was trapped on the elevator for 15 or 20 minutes before firefighters were able to reach her, police said. The woman was not injured, but was later taken to the emergency room because she was in shock, said Sgt. Kenneth Perkins of the Houston Police Department's Special Operations Division.