A commercial jet collided with a Black Hawk helicopter near Reagan National Airport, resulting in a crash. The incident occurred on Wednesday night, and flights at the airport have been halted. The cause of the collision is still under investigation, but air traffic control recordings suggest that the Black Hawk helicopter was instructed to circle and report traffic in sight, and the tower asked if the helicopter had the CRJ in sight before the crash occurred. The incident has raised concerns about air traffic control safety and potential staffing issues.