King County sheriff's deputies and medics responded to the scene, in the 12800 block of Martin Luther King Jr. Way South, at about 8 a.m. after the clerk called 911, said sheriff's office spokesperson D.B. Gates.
Deputies determined the man had driven himself to the store from his home on Sunset Avenue in Renton. The man told investigators his wife poured gasoline on him and set him on fire.
He was taken to Harborview Medical Center with burns to his head and back. His condition was not immediately available.
The King County Sheriff's Office handed over the investigation to Renton since the crime appears to have occurred at the victim's residence there.