HOUSTON -

First responders from around the country are honoring the fallen Houston firefighters at Reliant Stadium this morning. It's one of the largest memorial processions the City of Houston has ever seen.

Thousands of firefighters attended the memorial service for fallen Houston firefighters Matthew Renaud, Robert Bebee, Robert Garner and Anne Sullivan. 

All four died Friday after a five-alarm hotel fire at the Southwest Inn.

A procession of thousands of first responders made their way into Reliant Stadium, including some of the 14 injured in the blaze.

Then the families of the four fallen firefighters were introduced and escorted to their seats.

After Kelley Peters sang the National Anthem, Cardinal Daniel DiNardo said the opening prayer.

Both Texas Gov. Rick Perry and Houston Mayor Annise Parker spoke at the service.

"We will never forget their sacrifice," said Governor Perry. These are hard days, this is a painful day, but it's also a necessary day -- it's our duty to honor these four people."

"May 31, 2013 stands as the single worst loss of life in our history," Mayor Parker said. "I stand here today not as an individual, but as mayor of a great and grieving city."

"Our hearts are broken but our spirits are strong," Houston Fire Chief Terry Garrison said. "There is little we can do to help heal the hurt we feel. However we can stay strong in spirit, celebrate their lives and honor their service. We can continue to do our jobs to the best of our ability."

Chief Garrison then gave American flags to the families of the deceased firefighters.

Of the thousands of firefighters and apparatuses in Houston to pay their respects, crews came from San Antonio, Dallas and parts of Canada.

Officials said nearly 15,000 people attended Wednesday's memorial service.

Watch the memorial service live right here.

Click here to see photos from the memorial procession and ceremony.