Continental spokeswoman Julie King says Flight No. 546 landed Sunday around 1:30 p.m. at Lambert St. Louis-International Airport and was grounded about an hour before leaving for Chicago's O'Hare International Airport.
Federal Aviation Administration spokesman Lynn Lunsford confirms an "unruly" passenger tried to open the door.
FBI and airport police in St. Louis are questioning the passenger. Lambert spokesman Jeff Lea says the 34-year-old Illinois man got up 20 minutes after takeoff and said he had to get off the plane. No charges have been filed.
Aviation experts say it's impossible to open a door during flight because of pressurized air in the cabin.