While authorities focus on the cause of the US's deadliest aviation disaster since 2001, families are mourning their loved ones. Here's the latest.

Dozens of people are dead after a regional jet collided with an Army Black Hawk helicopter Wednesday night over Washington, D.C., officials said, the nation's first major commercial airline crash since 2009.

The Army official said that the pilots were on a routine training flight along a familiar flight path that isn't particularly complicated.