at least 119 people died in an explosion and a fire at a poultry slaughter house in china. some of them reportedly trapped by locked gates. this is a horrific story, raising new and urgent questions about working conditions in china. our senior international correspondent, nic robertson, is on the scene for us in northeast china. nic, what do we know, what happened? >> reporter: wolf, the stories that are emerging from here, people are saying some of the doors when they were trying to escape the building, there were about 300 workers inside the plant almost 24 hours ago to the minute when the fire began. about 100 managed to escape, some of them with very harrowing accounts. and what they've been saying is as they tried to get out, only one exit was opened. several doors were locked. people described an explosion and the place filling with black smoke, the lights going out. if i just step out of the way a little bit here, you can see