Audio Transcript:

LISA MULLINS: To Hungary now where emergency workers are struggling to keep toxic sludge from spilling into the Danube River. This spill began two days ago. Red liquid waste broke through the walls of a giant sludge reservoir at a factory. The wave of sludge flooded homes, roads and anything else in the way. Now workers have been feverously pouring plaster into a Danube tributary hoping to contain what some are calling Europe's worst environmental disaster in decades. The BBC's Nick Thorpe is covering the story, and today he managed to get to Kolontar. That's an area where the disaster started, in southwestern Hungary.

NICK THORPE: It's been perhaps the most shocking day so far. This is because we got access for the first time to the area worst affected by the disaster. Villages where a tidal wave of this red toxic sludge flowed through. Now we were able, thanks to an army pontoon bridge. We've had access to the very worst houses affected. Here are these houses with walls collapsed. This is the part of Kolontar where three people died and three or four people are still missing. People who used to live there, they've been very shocked to go into the houses that they rescued their relatives or fled from themselves just a few days ago. So, every one I spoke to today who used to live in that village said they can't imagine living there again. Their houses are still full of this red mud and there are sadder tales, too, from those people who are searching for missing relatives.

MULLINS: Nick, we know that emergency workers have been flooding into the area. We can hear what sounds like traffic behind you, maybe some trucks. Can you tell us what's going on right now?

THORPE: Right now, military vehicles have been arriving but also the local fire brigade. There's also a big operation now to bring in food and drinking water. But there is a huge amount of work to do here. A huge amount of areas, 14 square miles now under this red mud. And as I speak, more of that mud flowing down through the river system towards the river Danube, which is only 50 miles or so to the north of where I'm speaking from.

MULLINS: This is a huge concern that you mention right now. In fact, the European Union is warning that this spill could pose a serious environmental problem not just for Hungary, but also for the twelve countries around that area. Now, is there anything right now that they can do to prevent that? I mean what are they trying to do?

THORPE: One of the main efforts taking place is to dump large quantities of clay into the river system here. The idea of this is to bind the toxic chemicals, the heavy metals, in the rivers now because when I speak of rivers or streams, they don't look like normal rivers or streams. They are dark, red colored and really gushing quite high because all the rain which we've had in the past weeks and which may well have played a role in leading to this catastrophe in the first place. This is one of the big efforts, to dump clay in the rivers. The idea of that is so that the toxins would somehow sink to the bottom of the rivers to keep them in those small rivers now to prevent the toxins flowing into the river Danube. There are also plans, but I think these are still in quite the early stage, that if those efforts with the clay fail, that they might try to divert some of those smaller rivers into effectively man-made emergency reservoirs, farmer's fields, before the water, the toxins, reach the river Danube.

MULLINS: Alright, thank you very much. The BBC's Nick Thorpe in Kolontar in southwestern Hungary, reporting on the caustic sludge from a factory spill. Nick, thank you.

THORPE: Okay, thanks a lot.