How was Sir Thomas Booby died?

We are not apprised as to the cause of Sir Thomas' death, only that it was an accident (?).

"At this time an accident happened which put a stop to those agreeable walks, which probably would have soon puffed up the cheeks of Fame, and caused her to blow her brazen trumpet through the town; and this was no other than the death of Sir Thomas Booby, who, departing this life, left his disconsolate lady confined to her house."