Conversation so far:
How many people were in the group Belmont?
Three with a later addition of Dion.
Why did Dion DiMucci and Belmont break up?
There were musical, personal and financial differences between Dion and members of the Belmonts, and in October 1960, Dion decided to quit for a solo career.
Did Belmont continue producing music after Dion DiMucci's departure?
After leaving Laurie Records The Belmonts continued to record throughout the 1960s on the Sabina, United Artists and Dot labels.
Was I Wonder Why a success?
It was the group's first national pop chart hit, in 1958.
Was I Wonder Why the only success of the Belmonts?
Did the Belmonts released singles that had less success?
Their initial hit was followed by No One Knows and Don't Pity Me, which also charted the Billboard Top 100.
Why was the Winter Dance Party Tour ill-fated?
Holly and others decided to charter a flight to the next venue rather than travel on the tour bus. The flight killed all on board.
What happened on the flight to the next venue?

Question: Why Dion was not on the flight with the others ?
Self-contained rewrite: Why was Dion not on the flgith witht the others?