I can find no report of the details surrounding the passing of Dr. Campbell. From the U. of Nottingham page:
"Professor Campbell is survived by his wife, Kathy Campbell and his two adult daughters, Claire and Lauren Mills.
The funeral has been arranged for 10:30 am on Wednesday 24th October at Bretby Crematorium, Burton Upon Trent, DE15 OQE. If you wish to attend please contact Katherine.lawson@nottingham.ac.uk "