It’s been one week since American Eagle Flight 5342 crashed into the Potomac River, and the work has only begun to recover from the deadliest U.S.

Wednesday night’s crash of an American Airlines commuter plane in Washington could be one of the worst disasters for the Fort Worth-based airline in more than two decades.

While landing at Ronald Reagan Washington National Airport in Washington, D.C., on Wednesday shortly before 9 p.m., American Airlines Flight 5342 collided with an Army Black Hawk helicopter and crashed into the icy Potomac River.

Pilots and flight attendants are aware of risks, but commercial aviation tragedies have been infrequent in the U.S. for years.

The communication team at American Airlines had to activate a crisis plan it hoped it would never have to use after last week's midair collision of a passenger jet and Army helicopter that claimed 67 lives.