A Southwest Airlines plane had a close call with a private jet that entered a runway without authorization Tuesday morning at Chicago Midway International Airport, the Federal Aviation Administration (FAA) said. Southwest Flight 2504 landed safely after performing a go-around to prevent a potential collision. The FAA and the National Transportation Safety Board (NTSB) are investigating the incident, which occurred around 8:50 a.m. local time. NTSB Chair Jennifer Homendy said they don’t believe it was an air traffic control issue; it appears the Flexjet flight crew failed to listen and abide by air traffic control instructions. The private Bombardier Challenger 350 was operated by Flexjet, a company providing private aircraft on a “fractional ownership” basis. This close call occurred as both federal aviation agencies are investigating a series of safety incidents in recent weeks, including a deadly midair collision over the Potomac River near Ronald Reagan Washington National Airport, a fatal Medevac jet crash in Philadelphia, and a regional airline crash off the coast of Nome, Alaska, that killed 10 people. Roughly 90 minutes before the Chicago incident, an American Airlines flight was forced to cancel its landing at Reagan National to avoid a departing plane. Southwest passengers praised the pilot’s quick action. U.S. Transportation Secretary Sean Duffy said it’s imperative pilots follow air traffic controllers’ instructions.