Complex sentence: For 17 hours, the rebels battled Russian special forces supported by armoured vehicles and a helicopter, killing one of elite Alpha Group commandos and wounding another, until a tank belonging to the Russian Marines smashed the remains of the burned and gutted house.
Split into simpler sentences: For 17 hours, the rebels battled Russian special forces supported by armoured vehicles and a helicopter, killing one of elite Alpha Group commandos and wounding another. In the end a tank belonging to the Russian Marines smashed the remains of the burned and gutted house.