On Sunday he got his wish.
Diego, who has an incurable blood disease that makes his body age rapidly, captured countless hearts while wearing police dress blues during Bergen County's Police "Chief for a Day" event on June 3.
On Sunday, the 6-year-old first grader donned fire gear with his name on it.
"We caught wind of it when he said he wanted to be fireman," said firefighter Shawn Hagal, who shot the photos in the slide show above. "We wanted to make his wish come true."
After being sworn as a member of Fire Hose Co. No. 1, Diego was named chief.
The department then did a staged call on Division Avenue, with Diego giving commands over the radio and then flowing water through a firehose.
Diego got a police-escorted ride around town -- with lights flashing and sirens blaring.
"The police were so wonderful and helpful with this," Hagal said.
A barbecue followed -- but that wasn't all.
Firefighters collected donations and gave Diego a check to help fulfill another wish -- a trip to Legoland in Westchester.
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