On May 12 , 1957 , while on a spring ascent of Mount Slesse near Chilliwack , British Columbia with Geoffery Walker and David Cathcart she discovered the wreckage of TCA Flight 810 which had gone missing in December 1956 . Pigou and several local mountaineers , including Paddy Sherman and " Fips " Broda had surmised that Slesse was the most likely site of the Crash of flight 810 On July 30 , 1960 , while on an attempt to ascent Mount Waddington , she and climbers Joan Stirling , John Owen and Derrick Boddy went missing . Two days later a party from Seattle came across the site of their camp on the Bravo Glacier which had been obliterated by a large ice and snow avalanche 140 metres wide and at least 3 metres deep . The bodies of all four climbers were left in place , and a memorial was erected nearby on the south shoulder of Mount Jeffery by the Alpine Club
TCA Flight 810
Trans-Canada Air Lines Flight 810
Elfrida Pigou