The moment the DC10 rubbing strip fell onto the runway, the fate of all those people was sealed.
So if the runway had been swept before Concorde's departure, the accident would not have happened. Which leads me to ask:
1 - what is the normal frequency of take off / landings before runways are swept.
2 - would the runway normally be swept anyway in advance of a Concorde take off / landing given its known vulnerability of tyre damage.