Celebs, officials remember 9/11

Fifteen years after tragedy struck America when planes collided with the World Trade Center and the Pentagon, the country still mourns the horrific events.

Among those that have publicly offered words to express patriotism and recognize the historic day are Michael Bloomberg, John Kerry, Alyssa Milano and Ryan Seacrest.

Many people took to Twitter to honor 9/11 victims, including servicemen that lost their lives in relief efforts.