Complex sentence: For over six months he was actively engaged in experiments in television, then was killed when he accidentally received a shock of 6,000 volts while experimenting with television apparatus in the laboratory of his summer residence at Vernon, Connecticut.
Split into simpler sentences: For over six months he was actively engaged in experiments in television. He was killed when he accidentally received a shock of 6,000 volts while experimenting with television apparatus in his laboratory in his summer residence at Vernon, Connecticut.