Did I kill my yeast?

How bad is it if the temp crept up to 77f-78f for about a day or so. I had the carboy next to the fridge and I guess the fan was blowing on it. Fermentation was pretty active for the first two days, but airlock activity was low the day I noticed the hi temp. I moved it to the basement and the temp dropped to 68f but activity hasnt picked back up. My concern is that I'm going to get an incomplete fermentation.

p.s. noticed the hi temp. 3 days into fermentation

its fine. the high temps sped up fermentation, its probably just about finished...thats why you're not seeing much activity.

You'd need to go in there with a flame thrower, a machine gun, and about a dozen grenades if you wanted to kill your yeast. they're fighters.

I'd take a gravity reading. With high temperatures like that, yeast become very active: you probably ripped right through fermentation. What was your OG? If it's anything in the normal ranges or lower (below 1.060) there's a definite possibility it's finished.
If that is the case, it's going to take some serious extended aging to improve the off flavors on this one: I'm talking several weeks or even a couple months. At high temperatures like that, fusel oils are bound to develop. But don't worry, give it some time and you may be surprised...
Of course, unless the fermentation actually is stuck... Doesn't sound like it though...

Also, what was the temp at for the first couple days? If it was much cooler in comparison, there's a chance it might not be too bad after all...

It also depends on what kind of yeast you were using

Hey, thanks for the quick replies. The first couple of days were ok, within the recomened range in the kit instructions. (65-74f). Target O.G. was 1.062. reading when it was put into the primary was 1.0629.

Yea, you definitely should not be ripping through a big beer like that in 3 days. Regardless, as I said, give it some time. I wouldn't worry too much about it, I've heard of similar situations that turned out just fine.
Take your FG reading (it's probably done) and give it more time in the primary for the yeast to clean up. I'd let it sit for at least 2 weeks before bottling, then give it even more time in the bottles.

I just did a gravity reading. 1.019. My recipe (which is an IPA called Phat N' Hoppy, orig. from Appalachian Brewing Society) gives me a target final gravity of +/- 1.015. Will have been in the primary 1 week tomorrow. Still need to dry hop and rack to the secondary, sound ok you you?

Wait 2 more days since the last reading and take a second one. If it's still 1.019, then fermentation is complete.