A multi-agency search and rescue operation is underway in the Potomac River following a midair collision

A civilian airliner carrying 60 passengers and four crewmembers collided midair with a US Army Black Hawk helicopter over the Potomac River in Washington, DC, on Wednesday.

The incident occurred at around 9 pm local time. Flight 5342, operated by PSA – a subsidiary of American Airlines – was on its final approach to Runway 33 at Ronald Reagan Washington National Airport at the time of the disaster, according to the Federal Aviation Administration (FAA).

The US Army’s Sikorsky H-60 Black Hawk helicopter had a crew of three and was not carrying any VIPs, according to US defense officials. The exact number of fatalities remains unclear as emergency personnel from multiple agencies continue the search for possible survivors.

The FAA announced that Reagan Washington National Airport was temporarily shut down following the incident. The National Transportation Safety Board (NTSB) will lead the investigation into the crash.