 Flight 100 , a Douglas C @-@ 54B ( <unk> ) on the routing of Seattle @-@ Fairbanks @-@ Seattle , hit a mountain 3 @.@ 8 miles ( 6 @.@ 1 km ) from <unk> while on approach to Seattle . All five occupants perished . The cause of the crash was the pilot 's decision to enter an area of low overcast in mountainous terrain , as well as a navigation error . 
