This image was lost some time after publication, but you can still view it here.

Remember the power mishap in July that brought down 365 Main, the San Francisco datacenter? A similar incident took place today at the Dallas datacenter of Rackspace, a San Antonio, Texas-based firm which serves several local Web outfits. Unlike the July outage, which killed all the websites we waste time with — LiveJournal, Craigslist, and so on — this one took out some sites which really mattered. Laughing Squid, Scott Beale's popular Web-hosting company, went down, taking a long list of customers with it, and 37signals, the maker of Web-based software, went out — a serious matter, since 37signals actually charges for using its software. So what exactly happened at Rackspace?

Like 365 Main, Rackspace was hit by a utility power outage on Sunday. Unlike 365 Main, Rackspace saw its generators kick in, and all was well. This evening, however, a truck drove into a power transformer, causing it to explode. Rackspace techs described this in an email to customers, with admirable sangfroid, as leading to "additional power issues." Further word from Rackspace is that the chillers that keep the servers cool lost power when the transformer blew. An unknown number of servers were taken offline to prevent damage from excessive heat. Currently, the chillers are back online and Rackspace techs are in the process of bringing all the affected customers back online.

Interestingly, as Scott Beale of Laughing Squid points out, "Rackspace does not have a status page or blog." Beale, who's using a status blog to keep his customers informed, later noted that Rackspace does have a "customer portal" — I guess that counts as a blog — which they eventually updated late tonight.

Update 7:54pm: Laughing Squid is back online once again. So is 37signals.