Michael Brown and all other Bush administration officials are refusing to provide information on what they knew before during and immediately after Katrina hit. Maybe some of the Senate investigators should read the website of the National Geospatial Intelligence Agency which, in their online magazine, has a startlingly detailed description of how they created high resolution 3D maps before the hurricane and were able to assess the damage immediately by way satellite of imaging and see exactly where the damage was worst and where people were stranded. The NGA monitored the levees, hospitals, nursing homes etc. in real time yet astoundingly FEMA, Homeland Security and the White House all claim they were not aware of the extent of the damage for days and could not have rescued any of the peopled who died in those hospitals and nursing homes.
If I were a Senate investigator I would want to talk to the guy who was in charge of NGA during Katrina, who, of course, was recently fired by Donald Rumsfeld.