WASHINGTON (NEXSTAR) -- Transportation officials began the first of three days of investigative hearings Wednesday to find out what caused the deadly January plane crash that left 67 dead.

Family members who lost loved ones attended the hearing.

"Just a remarkable human being," Gwen Duggins said about her daughter Kiah.

She was among the 67 victims of the January crash near D.C., when an Army helicopter collided midair with a passenger plane.

"It's very tough to be here today, but I wouldn't miss it," Duggins said.

Duggins and other families who lost loved ones attended the National Transportation Safety Board's (NTSB) public hearings investigating what went wrong.

"This is an investigation. We are here to improve safety. That is our sole focus," NTSB Chairwoman Jennifer Homendy said

See Full Page