. >> we've now ruled out c orrosion, a preexisting leak and a piercing of the pipe by some excavation. so we know move on to looking for yet another cause. >> there's no outcome as far as, you know, what caused this horrific disaster in our community. but in fact, it's -- it's another step in the progression to find out what did. they have eliminated a few things which is good. >> reporter: and both jim moran and jackie speier have been to the ntsb investigation headquarters and they say that in looking at some of the other investigations going on there, similar to this one, there was a pipe rupture in florida. it turned out that that pipe rupture had to do with fatigue and not pressure in the pipes. so they are being cautious about not drawing any conclusions. there will be a town hall m eeting on that. but other than that, the ntsb is going to respond. they are going to have a news conference on that. ken pritchett will be following that for the 5:00 news. reporting live in san mateo, kraig debro, ktvu channel 2 n ews. >> thank you, kraig. >>> some rain put a damper on the morning c