Shares of Boeing fell in early trading on Monday, one day after a Boeing model 737-800 was involved in the Jeju Air plane crash in South Korea that killed scores of passengers. The stock price dropped more than 4% at the open of trading on Monday morning.

A team of U.S. investigators including representatives from Boeing have examined the site of a plane crash that killed 179 people in South Korea.

Data from the two black boxes will be instrumental in determining what caused the Jeju Air plane to crash at Muan International Airport, killing 179 of the 181 people on board.