He is trying to explain to these young children what a tragedy is. A young boy asks if his parents dying from a terrible illness is a tragedy.
“No,” Trump replies, “I would consider that a great loss”
A young girl asks if a train derailing, killing all 250 people onbard would be a tragedy.
“No, that is what you call an accident.” Trump again replies. “Look, say if I was flying in my presidential jet, and it crashed and I died, then that would be a tragedy.”
A little girl responds, “Well I agree, it certainly would be no great loss, nor would it be an accident.”