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.

Catch up quick: The passenger flight from Wichita, Kansas, was on approach to Reagan National Airport outside Washington, D.C., when it collided with the helicopter about 9pm ET on Jan. 29. Both plunged into the Potomac River in the deadliest aviation disaster in the U.S. since November 2001.

After American Airlines Flight 5342 and a U.S. Army helicopter collided mid-air, officials shared insight into the respective pilots’ communication with air traffic control.

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