At 2:50AM SLT (US Pacific) Second Life login servers apparently failed. It was brief, and thankfully just after minimum concurrency. At the time the problem commenced 28,788 users were online.
Linden Lab responded with unusual rapidity, and the problem was resolved by 3:10AM, a scant 20 minutes.
[Update: 3:35AM - Linden Lab posted a notice about the problem after the fact, and apologizing for the problems]
