TOM ALEX
REGISTER STAFF WRITER
Des Moines police are looking for a man who made threats to blow up a hospital helicopter. Police said the man made the threats Thursday night in front of Mercy Medical Center employees. After leaving the medical center grounds the man called the emergency room by phone and again threatened to bomb the Mercy air ambulance. Investigators say they know who he is but no arrests immediately were reported. Officials did not report what triggered the threats.