There's been an underground explosion at Post and Kearny, right outside the Ralph Lauren store at the Crocker Galleria. At around 10 a.m., people said they heard an explosion and saw the sidewalk rise up about 6-7 inches. Two manhole covers were blown off, as was a concrete cover, and the explosion blew up the glass front of the Ralph Lauren store. One woman was sent to the hospital with serious, but not life-threatening, burns. We wish her a speedy recovery.

The authorities suspect that an underground transformer blew, but the bomb squad is going in before they let PG&E look around. Parts of Post, Sutter, Montgomery, and Kearny have been cordoned off as the investigation continues.

Not a good week for PG&E, who just got hit with a possible $15 million fine for the Christmas 2003 above-ground transformer explosion too. In other news, there was also a bomb scare at Civic Center (which was cleared without incident) around the same time. Meanwhile, the authorities are also worrying that the beached whale we told you about in Half Moon Bay might explode as well. (Really!)

Also -- Flickr users, ABC News 7 wants to use your digital photos of the blast if you have any. And the SFGate.com website is running a little slow with all the traffic, so don't panic if it takes longer than usual to get to the Culture Blog.