refugees deal with every day, when those air sirens go off now, they go off for a reason. we had air strikes sort of nearby. the other thing that i did not expect were these nuclear sites. the power's off again at chernobyl. we don't really know what is going on there. we don't really know what's happening at the other power plant. we know the russians are using it as a base to house 500 soldiers. we know the staff at chernobyl has been working for nine days straight without a break. it was that that i did not expect to sort of have to deal with, and for the refugees who fled, and we're talking about 2.5 million people have already fled this country, double that number for internally displaced people. so many of them are ending up in lviv. the mayor of krakow said he's bursting at the seams, that the population there has raised 15%. do we ever think the refugees that made it to krakow are going to be worried about some kind of nuclear issue? i didn't think that would happen. that was unexpected. >> nbc's cal perry, you do more than just about anyone else to help us understand what's