Complex sentence: On her last mission in 2012, when she was on patrol in Afghanistan, she sniffed out a 30-pound (13.6-kilogram) IED and was continuing her search when she lost one of her legs when another IED detonated underneath her.
Split into simpler sentences: On her last mission in 2012, when she was on patrol in Afghanistan, she sniffed out a 30-pound (13.6-kilogram) IED and was continuing her search. She lost one of her legs when another IED detonated underneath her.