NEW YORK (WCBS 880) - Ten years later, Tom Von Essen retains a crystal clear image of a moment on 9/11/01.

WCBS 880′s Rich Lamb On The Story

The then New York City fire commissioner stood in the lobby of the burning One World Trade Center.

“You could see in the faces of the young guys especially, I thought, excitement and I looked at the faces of some of the older guys and I thought a little more trepidation, you know, more wisdom and more understanding of what they were getting themselves into,” he said.

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Von Essen says the big fire bosses were concerned and wanted the firefighters out.

“The chiefs had already made their decision early. They wanted that north tower evacuated not very long at all into the operation. But, you know, there were units that heard maydays of other units — they knew the fire officers, they knew the men – the people who were trapped, the firefighters that needed help. And some of that is where you find that really extreme bravery to just go on, continue going forward into harm’s way,” Von Essen told WCBS 880 reporter Rich Lamb.

But Von Essen said nobody knew that 102 minutes after the first building was hit, both towers would collapse into rubble.