captain john sudnik, ganci, and the chiefs dove into the entrance. >> i just remember the dust that day searing your lungs, like it was, like it felt like you were swallowing glass. >> pitch black. pitch black. we heard voices. are you okay? are you okay? that's when be made our way back up. then we got up to where the command post was. pete's mind went into rescue mode. >> pete ganci heard on the radio the cries of trapped and wounded firefighters. >> and then i remember him giving orders. i need truck companies. i need rescue company. tell them to come with me. >> as he before, ganci went into the debris to save his men himself. in the still standing north tower, many firefighters refused the order to evacuate while they were still carrying the wounded and disabled. ganci sent sal cassano to set up a new command post. 28 minutes later, cassano was on his way back. >> and then i look up and all i could see was the antenna from the north tower imploding. >> get out of the tower! major collapse! major collapse. >> i, in my mind, had to be resolved with death. >> regina wilson was on the