Can Katrina survivors file "wrongful death" suits against the govt?

I'm not a lawyer, so help me out here.

It just seems to me that writing editorials and blogging and ranting on the airwaves (while all good and important things) aren't quite enough when we have evidence of murder or manslaughter committed by certain government actors.

What's the law on this? If someone can document that their loved one died not because of Katrina, but because so-and-so from FEMA blocked a Wal-Mart water truck from delivering to whatever highway overpass they were waiting on... would whoever gave the order to block that water truck be liable in a wrongful-death civil suit?

I mean, there seem to be dozens of clear-cut cases where FEMA blocked aid from getting to people. DKos has a disturbing article here about these cases, where FEMA inexplicably BLOCKED aid from getting to people:

http://www.dailykos.com/storyonly/2005/9/5/16455/30830

Like I said, writing editorials and doing fund-raising is all well and good. But when someone commits murder via negligence, shouldn't legal remedies ALSO be pursued?

If they could prove (via autopsy) that a loved one died from dehydration and/or exposure instead of drowning, maybe.

I remember thinking, if this hurricane hit some area watering hole where rich people from NY and CT hang out, the govt would act quicker - fearing lawsuits from these savvy citizens.

I mainly wanted to know if people have the RIGHT to sue their govt officials in this way. Any legal wizzes out there?

government financial assistance, money to rebuild homes and the like. Normal in any situation like that. Families of 9/11 had to sign away right to sue.

As to whether there is a class action suit due to wreck lace endangerment by Bush, or those around him, purposely diminishing the ability of emergency agencies to function by putting unqualified & inexperienced in position of high authority & management in governance.. I don't know.