Southwest Flight 2504 performed a precautionary "go-around" to avoid hitting a private jet that entered the runway "without authorization."

In a TV interview, the chair of the NTSB, said that the near miss with a Southwest Airlines flight in Chicago was due to the Flexjet crew's failure to hold.

Pilots on a flight attempting to land at Chicago’s Midway Airport were forced to climb back into the sky to avoid another aircraft crossing the runway Tuesday.