It's not actually Waco, but a tiny
town called West, just north of Waco and south of Dallas, right off the interstate. I've driven by this town many times on my Austin-to-Dallas business trips; you can see the plant from the interstate. It's served by a volunteer fire department and many of those volunteers were working on the fire when the plant exploded.

I'm a RedCross volunteer and those of us trained in disaster relief are already being put on alert. I probably won't be heading up there for this since I don't have the specific training needed, but... we'll see.
It's more than likely
not related in any way to the deliberate and malicious act that killed and injured people at the Boston Marathon on Monday. West is one of many little Texas towns that grows up around the local plant or refinery and these sorts of accidents dot their history. For example, Texas City experienced something similar as recently as 2005 and an major event that nearly wiped out the town in 1947.
You can find full coverage of what's going on in West via either the
Austin American Statesman or the
Dallas Morning News.