From the exhibit shown above:
"On the morning of September 11, 2001, Battalion Chief Brian O'Flaherty witnessed the hijacked Flight 175 strike the South Tower of the World Trade Center from his post in the Brooklyn Navy Yard. Chief O'Flaherty responded to a command center inside the Marriott Hotel (3 WTC), a strategic location between the two towers. When the South Tower collapsed, showering steel and other debris onto the hotel, O'Flaherty was wounded. He gave his battered helmet to Battalion Chief Edward Henry, who had lost his own helmet during the chaos. Henry left the lobby, intent on aiding those in distress, while O'Flaherty remained inside to provide assistance to the injured. Both men survived, despite injuries, a fact that Chief O'Flaherty attributes in part to the helmet that protected them both."