DENVER, Colo. -- A passenger tried to open a plane door during a Frontier Airlines flight on Saturday morning but was subdued by airline staff and passengers, an airline spokesman said. Police and Transport Security Administration staff met Flight 514 after the plane landed in New York City and took the man into custody, said Frontier spokesman Joe Hodas. Hodas said the man would not have been able to open the door even if he had not been subdued. "You need special training to open the door," he said. There were 128 passengers and five crew members on the plane,...