6 Killed as Medical Choppers Collide

Six people were killed yesterday when a medical helicopter ferrying a patient crashed into another chopper with a patient as they headed for the same northern Arizona hospital. Three people in each chopper—including the pilots and the patients—were killed and a nurse was critically injured. An explosion in one of the helicopters after the crash also injured two emergency workers responding to the accident.

Investigators are examining the crash site to determine the cause of the accident. Officials said it's unusual for two aircraft to attempt to land at the Flagstaff Medical Center at the same time. The hospital doesn't have flight controllers, and it's up to pilots to coordinate landings. (More helicopters stories.)