MIAMI (CBS4) – The immense procession for two slain Miami-Dade police officers has arrived at the AmericanAirlines Arena in downtown Miami ahead of a public memorial where thousands of people are attending. 

Officers Roger Castillo and Amanda Haworth were killed Thursday while serving a warrant to a suspected killer, 22-year-old Johnny Simms. Simms was killed by another officer.

Two Miami-Dade Fire-Rescue fire boats were in Biscayne Bay behind the Arena shooting their water cannons as a sign of respect for the fallen officers. 

Bagpipe players marched ahead of the two hearses carrying the bodies of Castillo and Haworth as they arrived.

Mourners, including fellow officers and the general public, began arriving around 9 a.m. to the arena for the service. They arrived to see photographs of the two slain officers posted outside the arena on a huge screen.

Click here for a slideshow of the procession and memorial.

Among those speaking at Monday's services is Miami-Dade Mayor Carlos Alvarez, Miami-Dade Police Director James Loftus, Archbishop Thomas Wenski, Castillo's three sons and Haworth's father. Florida Gov. Rick Scott is also in attendance. 

Another American flag is also being flown outside the Arena in Miami. It's the United States Honor flag, which was flown at Ground Zero in New York and other places around the nation. 

The procession, which caused major road closures, traveled on the Palmetto and I-95 before reaching the Arena.  Many people in the community stepped forward to watch as the convoy passed as a show of respect for the families of the fallen officers. 

Haworth, a 44-year-old single mother, left behind a 13-year-old son; Castillo, 41, whose wife is also a Miami-Dade police officer, is survived by three sons, ages 9 to 15.

In the program handed out Monday's service, there's a note from the family.

It reads: "The Castillo and Haworth Families would like to express their sincere thanks to the law enforcement community for your overwhelming support and prayers. Roger and Amanda were both proud to wear the badge and enjoyed every moment of their chosen careers. We appreciate the outpouring of assistance from all of the agencies involved and the community as a whole. Your kindness has given us the support and strength to face the most difficult time that one can possibly imagine. May God bless you and keep you safe."

When the memorial is over at the AmericanAirlines Arena, the funeral procession will head back to Vista Memorial Gardens in Miami Lakes for burial, which will be private.