My then-employer's building had its basement flooded; we were on floors 19 through 25, but our electricity and phones and Internet were gone --- and this, three weeks before the end of Q2. Our developers and IT people hauled computers down the stairs, and we moved to temporary space for several weeks, but we still missed, that is, we didn't achieve the sales and revenue targets that we had forecast for analysts.
I'm given to understand that because of the lessons learned from Allison, Houston isn't quite as vulnerable to flooding any more.
[1] http://en.wikipedia.org/wiki/Tropical_Storm_Allison#Texas