Complex sentence: Fire investigators suggested that the death was either caused by an electrical arc that shot out of an outlet and set fire to Mott, or a gas leak however, there was never any evidence to fully or even partially support that claim.
Split into simpler sentences: Fire investigators suggested that the death was either caused by a gas leak or an electrical arc that shot out of an outlet and set fire to Mott. However, there was never any evidence to fully or even partially support that claim.