I didn't cheer when Nathan flew in. I just said, "Oh, Nathan." :(

I hope he made it out of the blast radius in time. But there might not have been enough time. The timing would have been iffy, since it would have been difficult to know exactly when Peter would explode. If they timed it wrong, Peter would get too close to the ground, or Nathan wouldn't be far enough away. Odds are Nathan is dead. At least it was a nice respectable death, unlike asshole!Nathan being killed by Sylar.