He may have had a heart attack , or a pulmonary edema from altitude sickness , but either way , the mountai n probably killed him .
Duff apparently had vomited in his sleeping bag , and choked to death .
Duff may have had a heart attack , or a pulmonary edema from altitude sickness , but either way , the mountai n probably killed Duff .
Duff apparently had vomited in his sleeping bag , and choked to death .