NEW YORK- As millions of people in the U.S. prepare for Thanksgiving, security remains tight in New York ahead of the annual Thanksgiving Day Parade.
    
Police Commissioner William Bratton says more than 2,500 officers will be along the parade route for the Macy's Thanksgiving Day Parade on Thursday.
    
More than 3 million spectators are expected to attend.
    
It has been a New York tradition since 1924.
    
Mayor Bill de Blaio says the event kicks off a season of appreciation. He says New York residents must remain vigilant but not fearful after the attacks in Paris.
    
Officials have said there are no known, credible threats against New York.
    
Thousands of people gathered in Manhattan Wednesday night to watch workers inflate 17 enormous balloons that will fly in the parade.