South Korea plans to review the concrete walls positioned just beyond the end of some airport runways after an aircraft attempting an emergency landing smashed into one just over a week ago, killing almost everyone on board.

South Korean officials are struggling to determine what caused a deadly plane crash that killed nearly 180 people on board, with the nation saddened, shocked and ashamed over the country’s worst aviation disaster in decades.

Boeing shares were lower Monday after South Korea announced it is launching an investigation following the deadly Jeju Air crash over the weekend that involved a Boeing jet.