I'm going to answer with Pokemaster's assumptions, since I talked to him today.
The DB was down.
I emailed Pokemaster today and we talked about it on GChat. At first, he thought it was some kind of server error. In a few minutes, the the PokeBase was up. Then, it went down again.
Pokemaster now believes that we've been hit by a DDoS. For those who don't know what it is, it's a "Distributed Denial of Service", it's what happens when a bunch of computers all try and load the site at once, causing massive overload to the site (Pokemaster).