In response to the passing of troop greeter Bill Knight, veterans and their family members have taken to social media to remember the World War II veteran, who estimated in 2011 he’d shaken hands more than a half-million troops leaving for or returning from the war in the Middle East.

On Twitter:

On Facebook, many have taken to the The Way We Get By page to offer condolences:

Paul House: I met Bill Knight many times as our son Joel was deployed to Iraq and when he came home. Bill will be greatly missed and what a great deed Bill did for our men and women in uniform and for his service to our great nation.

Warren C. Cook: Very special, RIP Bill, one of the greats!

Carolyn Emery: They do not make like them like him anymore. He and my Dad knew each other.

Beth Grady: Oh how sad. He was an inspiration for remembering those who served overseas. God Bless You.

Pam Mundy: Bill is and always will be an American Hero. Rest in peace. To his family and friends, we are truely sorry for your loss