army staff sergeant ty carter received the medal of freedom at the white house last hour. he's the fifth living recipient from the wars in iraq and afghanistan. during a fire fight in 2009, carter helped kill enemy troops, resupplied ammunition, and risked his own life to save an injured soldier under attack. before today's ceremony, the sergeant sat down with nbc news chief pentagon correspondent. >> there was something very different. the sound of the gunfire was nonstop. usually you'd hear the putter of a burst, but there were so many bursts going on all the time. it was a constant -- almost like a rock concert, where that constant buzz or hum is always there with the addition of explosions and everything else. >> and speaking of heroes, you're going to want to see this. boston firefighters who were on duty the day of the marathon bombings were honored today. 150 of them received