If the airline cancels the flight due to bad weather or technical problems and the passenger does not want to go to another flight, they can request a refund of the ticket.
In the event of the death of a passenger or companion, the passenger is entitled to a refund of the ticket.
KLM Cancelation Policy says If your domestic flight is delayed by more than 90 minutes. You can also request a refund if your return flight is on the same day.