Sounds like frost damage to me. Is the core all right? I would cut off the effected leaves and pray for the rest of the plant. I would not move it right now. That said. I really do not know A attenuata. that well. I do know they are very cold sensitive. I can not grow them outside in Austin. I am speaking mostly what I do with cold damaged agaves here in Texas. DO NOT WATER them. they are probably fighting off rot in their roots too. Good luck . They are still questionable for months. I had an Agave weberi that looked pretty good and it keeled over from root rot 2 months after it had a killing 11 degree frost. It is hardy till 15.

Agave attenuata show frost damage easily. It can be as minor as yellow/ brown spotting, or you may see complete melting of the foliage.

In my experience, however, the central growth spike where new leaves have yet to unfurl remains clean and undamaged after a frost or light freeze event. In time, it will outgrow the ugly leaves and look good again.

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In a freeze event with rains, the new growth spike can also start to rot out, I have seen this happen locally after last week's freeze. If you grow Agave attenuata, it is best to protect it against frost if you want a perfect looking plant, because they can start to show damage even if it doesn't quite drop below 32F.

The core appears okay. It wasn't a hard frost (I don't think it got below 32F) so hopefully it will recover. Thanks for all of the advice.