Frontier Airlines Flight 3345 departed San Juan, Puerto Rico, bound for Chicago O'Hare on Sunday and was diverted to Miami International Airport after a passenger attempted to open exit doors and access the cockpit. The aircraft landed safely, the passenger was removed by law enforcement, and the flight continued to Chicago several hours later. Reports cite crew de-escalation efforts and an FAA-noted disturbance, with one unverified claim of passenger restraint.