Complex sentence: Pittston responded to the strike by hiring replacement workers for those union members who went on strike and to ensure that production would continue, Pittston also had help from the state police to escort the replacement miners and coal trucks across the picket line.
Split into simpler sentences: Pittston responded to the strike by hiring replacement workers for those union members who went on strike. To ensure that production would continue, Pittston also had help from the state police to escort the replacement miners and coal trucks across the picket line.