What problem does the speaker mention?

M: Hi, everybody. Quick announcement about this weekend. Our office building will be undergoing some repairs Saturday morning and, uh, the electricity will be off for about three hours. For any of you planning to come in on Saturday, power should be restored by one o’clock. So you might want to wait until later to come in, when everything’s up and running. I’ll notify you by e-mail once the work’s done.
Number 89.What problem does the speaker mention?
Number 90.What does the speaker imply when he says, “you might want to wait until later to come in"?
Number 91.What does the speaker say he will do?