Investigators from the NTSB and Boeing were expected to join the investigation into South Korea's deadliest air crash.

A deadly plane crash Sunday killed nearly 179 people in South Korea, an enormous tragedy that led to a week-long period of mourning being declared in the country. As the victims and their families deal with the aftermath,

South Korean officials are looking for the cause of a passenger jet crash that killed 179 people, in one of the deadliest disasters in the country’s aviation history.