br pFlights were grounded at Seattle–Tacoma International Airport on Friday, August 10, after a Horizon Air plane was stolen from the airport before crashing near Ketron Island.ppIrwin Downes recorded a cloud of smoke billowing from Ketron Island after the crash. The Pierce County Sheriff department informed the publica that the crash was caused by a suicide. Alaska Airlines, Horizon Air’s parent company, confirmed on Facebooka that the plane was stolen at about 8 pm and subsequently crashed.