Two planes nearly collided as they were about to take off at Washington, D.C.-area Reagan National Airport Thursday morning, prompting the Federal Aviation Administration to launch a formal investigation into the near-catastrophic air traffic control failure. According to audio of the incident obtained by CNN, an air traffic controller cleared a JetBlue plane to take off just seconds before another cleared a second Southwest Airlines flight to cross the very same runway. Luckily both controllers immediately recognized the situation and yelled out for both aircraft to stop. “JetBlue 1554 stop! 1554 stop!” the tower controller calls out. The ground controller ordered moments later: “2937 stop!” JetBlue confirmed the incident to CNN, saying its aircraft was inspected and promptly departed. “We are aware of the incident and are working with the FAA to fully understand the circumstances,” Southwest Airlines added in a statement to CNN. It’s unclear whether the National Transportation Safety Board will launch its own probe.