A Southwest flight appeared to take off from a closed runway that had a vehicle on it without being cleared by air traffic control

• A Southwest Airlines flight took off from a closed runway despite air traffic control warnings.
• The pilots didn't communicate with the tower or other planes, an ATC recording suggests.
• The NTSB is investigating the latest incident involving a Southwest plane.

A Southwest Airlines flight appeared to take off from a closed runway that had a vehicle on it, despite air traffic control trying to warn the pilots.

The National Transportation Safety Board is investigating the incident.