Must have been horrible for all the players on the field, especially witnessing the delayed reaction, Hughes appears to be just moderately hurt and than collapses(that unbroken fall couldn't have helped) to his eventual death.
Incredibly freak situation, there have been a couple of close calls in baseball over the years but Cricket is even more surprising.
Can't remember many deaths like this in sport, occasionally a soccer player with a heart condition has died on the field, Bill Masterson died in the NHL years ago from a fall though that was pre helmet days.