I spoke to one of the Club agents at South Station today. The event happened five weeks ago: a pipe burst in the ceiling of the women's room. The ceiling collapsed. Water poured out for 45 minutes before it could be shut off.
The area is still being dried out. Then everything will be ripped up and replaced -- a complete renovation. They are in the process of design and awarding a contract for the work. It will be at least two to three months before the work is completed.
There's a new, very small Acela waiting area within the Amtrak ticketing office, roped off with chairs and electrical outlets, and the WiFi is working. If you ask, the agent will get you water and a newspaper.