Tube amp down, need guidance from the experienced

I listened to my McIntosh MC275 Mk.IV all day yesterday without issues, as usual. Today I turned it on and left the room. Didn't pay attention at startup. Ten minutes later I realized it was not on. Eventually I figured the fuse had been blown, and replaced it. Turned it on again and found one KT88 was not glowing and cold. The rest of the tubes, both small signal tubes and KT88, were all on. Didn't attempt to play anything, turned it off, and here I am.

Obviously I need to replace the KT88, preferrably all of them. Unfortunately I don't have any spares on hand. What I'm anxious about, though, is to figure out if anything else was damaged. Is there reason to believe something else might have been damaged when this tube went off? First time a tube fails for me, and have seen a number of horror stories told on the net.

Thanks much!