They played freshman football at Cortez High School, served as groomsmen at each other's weddings, and even lived together for a while. As young men, both joined the Phoenix Fire Department, where Nick's dad was chief. Both built successful careers and eventually rose to deputy chief.
In their high-school days, Khan was such a frequent guest that the Brunacinis regularly set an extra place at dinner. Later, when Khan and Nick became firefighters, they posed in uniform with Nick's younger brother, John, for a professionally shot "family picture" that for years hung proudly on a wall in the Brunacini home.
So when Nick's dad, Alan Brunacini, retired last summer after 28 years as fire chief, many firefighters were happy that Khan was chosen to replace him. Chief Brunacini was greatly loved; by giving the job to his hand-picked successor, the city was keeping the job in the family.
But in the seven months since Khan took over, everything about his relationship with the Brunacinis has changed.
Nick Brunacini doesn't speak to his old friend anymore.
And 69-year-old Alan Brunacini "Dad" not just to Nick and John, but to many firefighters is in virtual exile from the department he built.
On Khan's first day on the job, he unveiled a department restructuring. He'd been working on it quietly for months, consulting union officials and private contractors, but never once discussed it with the old man.
No one could blame the new chief for setting up his own administration. But to the Brunacinis, the changes weren't a housecleaning.
They were a demolition.
Alan Brunacini was stunned to see his sons transferred, his best friend demoted, his training program scrapped. Even worse, the new chief told Brunacini that he'd have to stay away from the department he ran. Khan wanted the former chief to move on.
The fallout from that request has caused a deep rift in the once close-knit fire community a rift that's ostensibly over how to run the department, but one that could never be only about the department.
Sure, Alan Brunacini frets that Khan's changes are wrecking the department that he built. But more than anything, the heart of the problem is that this is family.
Somehow, it's not surprising that Nick Brunacini has compared his former best friend to Fredo Corleone. To the Brunacinis, the new chief didn't just make personnel moves. He betrayed them. For his part, Khan won't even talk about his former best friend. He's clearly uncomfortable talking about his fallout with Alan, too.
Now even Phoenix firefighters who aren't close to Khan or Brunacini are paying attention to the feud. The forum page on a Web site started by Nick Brunacini, www.bshifter.com, has exploded with recriminations and has become a must-read in fire stations across the city.
Everybody's got a theory for what's transpired.
Some suggest that Khan had to remove all traces of his predecessor to make the job his own. Brunacini was one of the nation's most respected fire chiefs; filling his shoes would intimidate anyone. Khan may have been too insecure to deal with his lingering presence.
Others blame union officials, particularly the president of the United Phoenix Fire Association, Billy Shields. They say that by the time Brunacini retired, Shields could barely tolerate his presence and that Khan's personnel moves have Shields' fingerprints all over them.
But others argue that the plan was the work of Pat Cantelme, Shields' predecessor in the union and now owner of a private ambulance company. In the past, Cantelme had his eye on the lucrative Phoenix ambulance market. Some believe that interest played into the department's restructuring, though Cantelme vehemently denies it.
Even Khan's most vocal accusers don't believe he's in it to make money. But they do suspect him of being used by people who are. Indeed, one fire department retiree who helped plan Khan's restructuring has been awarded a fat consulting contract.
Ultimately, though, this story isn't about money. It's about a band of brothers that's become bitterly divided.
Friends says that Alan Brunacini and his wife, Rita, are shocked by Khan's actions.
"Bobby was just like one of his kids. And that was the most tragic thing to both of them, Alan and Rita both," explains Robert "Hoot" Gibson, one of Alan's best friends, who himself was affected by Khan's personnel changes.
"What Bobby has done to them it shouldn't be that way. It didn't have to be that way. And it just tore those two up."
At 5'7", Alan Brunacini is a short man. But in national fire service circles and yes, these circles really do exist Alan Brunacini is a giant.