base. >> captain thomas lafave: they know what my purpose is when i roll out with that buffalo. and they've watched it enough to know exactly what that vehicle does. >> pitts: you leave the gates and people are watching you, you think? >> lafave: roger. yep, every time we leave. >> pitts: every day, they're going to be out there trying to kill you. >> lafave: every time we leave. >> pitts: their job was to clear a road so the base commander could drive safely to a meeting with a local official 12 miles away. outside a village, the buffalo, the most highly-armored vehicle in the convoy and the biggest target, stopped to dig for a bomb because the squad was attacked here just the week before. >> clear. no bomb. >> pitts: the convoy moved on. but six minutes later... >> buffalo hit. >> secondary [no audio]. >> pitts: the buffalo filled with smoke as two powerful bombs buried in the dirt road exploded, engulfing the vehicle in a huge cloud of dust. despite their training and experience, the squad never saw it coming. >> 3-6, 3-6-6, we're good, we're good. >> 10:00, there's a guy run