Harry forgot that:

	When the power cord is cut, electricity can flow into his body.
	The cut cord can energize the ground around him.

He should have remembered:

	To only use a proper outdoor extension cord.
	To never cut a wet lawn with an electric mower.
	It would be better if the cord were plugged into a G.F.C.I.

G.F.C.I. (Ground Fault Circuit Interrupter)

Is designed to stop the flow of electricity should a fault occur in the cord or appliance. The interrupter can help prevent electrical shocks.