In total, 11 soldiers from the 507th had been killed, while six others were captured, including Private First Class Jessica Lynch, Specialist Shoshana Johnson and Private First Class Lori Piestewa. Piestewa died of her wounds soon afterward. After a delay, the Marines of 1st Battalion, 2nd Marines (part of 2nd Marine Expeditionary Brigade), attacked Nasiriyah from the south, using amphibious assault vehicles (AAV's) and Cobra gunships. During this action, the Marines captured two bridges spanning the Euphrates River that were defended by Fedayeen and Ba'ath Party guerrilla soldiers. In heavy fighting, several Iraqi platoon-sized units, two ZSU-23-4 "Shilka" anti-aircraft weapons and several mortar and artillery positions were destroyed by a combined force of M1 Abrams tanks, Cobra helicopter gunships, and the artillery of 1st Battalion, 10th Marines.