Among the 67 people killed in the collision on Wednesday night were two flight attendants. Danasia Elder was 34 and a mother of two. Ian Epstein, also a parent of two, was 53.

Following the Jan. 29 American Airlines plane crash in Washington, D.C., that killed all 67 involved, investigators have sought to understand the tragedy. Here’s everything to know so far.

American Airlines’ largest plane, the 304-seat Boeing 777-300ER, will begin flying daily out of Charlotte Douglas International Airport to London Heathrow starting on Nov. 5.