on the air, the drama is still playing out in the desert. The workers, including americans taken hostage by terrorists with ties to al qaeda. The algerian army is still trying to end the dangerous... See More
on the air, the drama is still playing out in the desert. The workers, including americans taken hostage by terrorists with ties to al qaeda. The algerian army is still trying to end the dangerous showdown. We are hearing harrowing stories from those who managed to get out alive. Martha raddatz is overseas following every new twist in this story tonight. Martha? Reporter: Diane, we now know that one american is dead. The family has been notified. As this bloody assault intensifies. Algerian special forces moving in, trying to end this stand-off with the terror group once and for all. Reporter: The assault tonight is a deadly mission. The gas plant has been ringed with explosives by the hostage takers, not to mention all that gas. It's a dangerous mix. Images tonight on arab tv of the carnage. Numbers are fluid. One report saying 12 hostages have been killed and more than a dozen of the terrorists. Aside from the one american who was killed, a small number of other americans believed to be at the facility are unaccounted for. But american officials are sending a strong message. Those who would wantonly attack our country and our people will have no place to hide. Reporter: Once militants stormed the complex, they smashed down the doors of the residential building, in a hunt for americans and other foreigners. Another witness described to the "new york times" terrorists shooting a european in the back while other hostages watch period. STEVEN fen McFaul of irltd reportedly described to his family how he escaped president kidnappers had him in a convoy of vehicles when the algerian army bombed them. His car was hit, but in chaos he made a run for it along with others. I'm just glad to be out. Some colleagues are still is there at the . Reporter: Many others who managed to escape this terrible ordeal are here in europe at military bases or on their way in u.S. Military aircraft. But so many more remain unaccounted for.
This transcript has been automatically generated and may not be 100% accurate.