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.

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

The deadliest plane crash in U.S. history was in May 1979, when American Airlines Flight 191 lost an engine during takeoff at Chicago O’Hare International Airport and crashed moments later, killing 258 passengers and 13 crew. Two people on the ground also were killed.