it's a very dangerous situation in this city still. >> brian todd reporting live from joplin, missouri. the missouri governor jay nixon has rolled out the national guard to help with the search and rescue mission. and earlier on cnn's "american morning," he stressed, the danger is not over. >> with the gas lines that have been broken, fires have been breaking out all night. we do have -- the good sign is we have sufficient water pressure for firefighting, so firefighters are able to deal with those issues. but we're going block by block, and the lack of power, it's a very, very precarious situation. folks should allow the professionals that are coming in to assist to get a full sweep there. like i say, we stand ready to put additional guard boots on the ground if necessary. >> and stick around. in about a half hour, i'll talk live to the missouri governor you just heard, jay nixon. he'll bring us up to date on the latest numbers, and they're still searching for survivors. joplin has a population of 49,000. witnesses tell us the twister was a half to three quarters of