Tyler Seddon turns 7 on Thursday and has been named honorary police chief of his hometown of Burrillville.
He's being driven around in a police cruiser. Hundreds of firefighters, police officers and first responders from several states also are throwing him a birthday party.
Tyler's mother, Rachel Seddon-Dunn, put out an appeal on social media asking first responders to send birthday messages to her son. He's battling leukemia for the second time, and his family is looking for matching bone marrow donors.
Tyler received birthday cards and other messages from all over the country, including from the Los Angeles Police Department, which sent a video featuring its chief.