Here are the latest developments in this story:
A total of 21 people were hospitalized, including one female police officer. She was in good spirits, the chief said.
Seven other people who were hurt declined medical transportation.
Some of the bystanders who helped care for the injured were emergency responders who were tourists in town for Mardi Gras, the chief said.
Harrison said there is no indication the accident was an act of terrorism.
Video from CNN affiliate WDSU showed a gray pickup truck that had crashed into a dump truck on a median near the intersection.
Witnesses told the station the pickup came down one of the streets and struck several cars before hitting people in the crowd watching the parade.
"I saw the gray truck flying down Carrollton Avenue," a female witness told WDSU while clutching her strands of Mardi Gras beads. "He sped up and he lost control and you could see (the truck) was getting ready to turn and I knew he was going to run into all those people."
The accident happened around 6:42 p.m. (7:42 p.m. ET).
The parade was coming down Orleans Avenue before making a right onto Carrollton.
The Endymion parade is one of the most popular parades leading up to Mardi Gras, which is Tuesday, and one of the most family-oriented. Many parents brought their children to the event.
Truck rams New Orleans crowd during Mardi Gras parade; 28 injured
By Steve Almasy and Nick Valencia, CNN
Updated 11:46 AM ET, Sun February 26, 2017
http://www.cnn.com/2017/02/25/us/new-orleans-mardi-gras-parade-accident/