At 26 seconds you can hear the Engine sounding the Mayday evacuation alert. They do it in case the radios are down or can't be heard. You can't not hear the Engine airhorn. It means all firefighters, inside and out, return to your apparatus or staging area immediately and report to your officer. The Incident Commander and RIT officer will do a head count against the tag system. If anyone is missing the Rapid Intervention Team goes to work. They are specially trained firefighters who stand by at structure fires specifically to recover down firefighters not to fight the fire.

I can't wait to read the after incident details. It's got to be one hell of a story.