Right now the Astros are the only team with a negative WAR in baseball.
2010 Astros total team WAR: -2.3 (Fangraphs); -0.3 (B-R)
2003 Tigers total team WAR: -17.4; -4.2
Since 2003, only one team has put up a negative team WAR: the 2004 Tigers, and that’s only by Fangraphs’ standards.
So they could make a run at being the worst team in baseball history. They might need to trade Roy Oswalt and Lance Berkman to accomplish that, but they’re in the ballpark.