Complex sentence: After repelling the largest attack wave, the Annex receives word from ISR that help is en route, but before it can arrive, the militants launch a mortar attack that wounds one of the DS agents and kills both Woods and Doherty.
Split into simpler sentences: After repelling the largest attack wave, the Annex receives word from ISR that help is en route. The militants launch a mortar attack that wounds one of the DS agents and kills both Woods and Doherty.