If the LLM competitors have their own data centers, what would cause them all to crash at the same time?

I just happen to be experimenting with 4 different LLMs this morning when they all crashed at exactly the same time.

I could understand if it's a time of day surge, but I would expect at least one of them to stay up during that. Students are back? Maybe they're seeing much larger usage than expected?

I don't see any DNS outages or anything that shows a large outage is happening.

What else could it be?