An NYPD Emergency Service Unit hardhat and folding shovel used on Sept 11, 2001 and during the clean-up period at ground zero, by police officer Kenny Winkler of NYPD ESU 1.

Kenneth Winkler was off-duty from a night shift as an officer with the New York Police Department's Emergency Service Unit, on the morning of the attacks. He nonetheless joined his colleagues on their vehicle and they raced toward the World Trade Center, and stayed in the vehicle outside to coordinate communications between different parts of the force. After the South Tower collapsed, he ordered everyone still inside the North Tower to leave. He had to abandon the vehicle after the North Tower collapsed, and set up a new command center nearby and continued to try and coordinate communications. Later, he would work on the pile during the rescue operation, wearing his NYPD hardhat and carrying his hand shovel, and returned periodically to the site during the following nine-month clean-up operation.

Shoes of survivor Roger Hawke during his evacuation from the 59th floor of the North Tower.

Roger Hawke worked at Sidley Austin, a law firm that had offices on the 57th through 59th floors of the North Tower. This was not the first attack on the World Trade Center he had lived through: He was there in 1993 too, when bombs exploded at the complex. Soon after the first plane crashed somewhere above him on 9/11, he made his way to one of the increasingly crowded and hot stairways. It took about 90 minutes to descend to safety. He headed on foot to the apartment of his daughter and son-in-law on the Upper East Side, arriving there caked in ash, leaving his dust-choked shoes at the door before entering. His 4-year-old granddaughter jumped into his arms but then recoiled at the smell of smoke permeating his clothes: "Papi is on fire from the inside," she said.