Ironworker construction helmet belonging to Larry Keating.

Larry Keating was an ironworker foreman who helped oversee the removal of wreckage from the World Trade Center site during the nine-month clean-up operation following the attack, and was chosen by the ironworkers union, Local 40, to represent his colleagues at the ceremonial removing of what became known as Last Column - an upright piece of the towers that had become covered in mementos from the clean-up workers and from which flew an American flag. He wore his hardhat throughout the clean up, and continued to wear it proudly for site visits until his death in 2011 from a heart attack.

A Port Authority Police Department uniform hat, badge number 899, and Port Authority Pipe Band hat belonging to victim Liam Callahan.

Liam Callahan was a Port Authority police officer who had been commended for his "heroic actions" after responding to the 1993 World Trade Center bomb attack, and was a first responder on the morning of 9/11. Even after the towers collapsed, Joan, his wife, continued to hope he might somehow turn up in time for the celebration of their 20th wedding anniversary the next day. He was killed at the age of 44. His family donated his Port Authority police uniform hat and the uniform he would wear as a drum sergeant in the force's Emerald Society Pipes and Drums band.