Conversation so far:
what was Edmund Hillary's personal life like?
Hillary married Louise Mary Rose on 3 September 1953.
and how was his married life with louise?
CANNOTANSWER.
what more is known about his personal life?
They had three children.
what more is known about his children?
Peter (born 1954), Sarah (born 1955) and Belinda (1959-1975).
did the children also take to expedition and help hillary?
His son Peter Hillary also became a climber, summiting Everest in 1990.
what about the other children?
Louise and Belinda were killed in a plane crash near Kathmandu airport shortly after take-off.

Question: what were they doing in Kathmandu?
Self-contained rewrite: what were Louise and Belinda doing in Kathmandu?