We know this is a difficult week, one filled with heart-wrenching memories for all Americans.

As we remember all who lost their lives on Sept. 11, 2001, the USO is asking 50,000 Americans to join us in thanking the brave heroes who continue to sacrifice so much to keep us safe and free. We've seen an outpouring of support from this community since we first reached out yesterday, but we're still waiting for you to add your name.

In the 23 years since that shocking and devastating day, so many brave Americans have answered the call to serve. 24 hours a day, 365 days a year, they risk their lives to protect us — our children, our families, our freedom. Please show your gratitude for them: Sign the card now.

Thank you,

—The USO