The helicopter collided with passenger plane carrying 64 people and crew, crashing into the Potomar River late on Wednesday night.

The number of people onboard and any fatalities is unknown at this time. The plane can carry up to 65 passengers and four crew members.

The Army Black Hawk helicopter that collided with an American Airlines commuter plane near Reagan Washington National Airport in Virginia Wednesday was on a “training flight” when it crashed into the Potomac River, according to the military service branch.