Yankees, Mets Honor New York First Responders Sunday, 21 years

Mets, Yankees to wear first responder caps for 9/11 remembrance game vs. Yankees

Heartbreak and hope: Members of 2001 Mets reflect on their role in helping NYC recover from 9/11

Mets, Yankees wear NYPD, FDNY hats on 9/11/2020

Saluting our first responders on 9/11, Commentary

Mets, Yankees and more pay tribute on 9/11 20th anniversary

20th Anniversary of Attacks Marked by Mets, Yankees - Fire Engineering: Firefighter Training and Fire Service News, Rescue

How Sports World, Teams Plan to Honor 20th Anniversary of 9/11 – NBC New York

NY Yankee Paul O'Neill's No. 21 to be retired on Aug. 21

New York Mets, in partnership with the National EMS Memorial Foundation, to host EMS Appreciation Night at Citi Field