Condo collapsed. We now know 10 people are confirmed dead, 151 others remain unaccounted for. Meantime, questions continue about what this could have happened. Joining us to talk about that is uc Berkeley Professor of structural engineering. Thank you for being here. Its been just about five days, do you have a better sense now at all of how this happened . Thank you for having me. Well, it will take a while until we know exactly what happened. Considering that this building was constructed 40 years ago, one can only speculate the code provisions that were followed at that time were not as robust as what we have these days. That could be one of the things investigators could look at. Terms of this kind of collapse, it is very rare. These buildings go through very detailed Design And Construction processes. For this to happen, there has to be some abnormal kind of affects. It could be things related to the foundation, is related to the soil. We know that florida has some susceptibility