The married father-of-two had served with the department for 21 years.
Police arrived on the scene within 15 minutes and arrested the suspected shooter, 67-year-old Robert Somerville, and recovered a .380 caliber handgun. He was booked on homicide and weapons charges:
Detectives arrested Robert Somerville, 67, in connection to the shooting death of Stockton Fire Captain Vidal “Max” Fortuna. Somerville was booked into the San Joaquin County Jail on homicide and weapons charges. The weapon located at the scene was a .380 caliber handgun. pic.twitter.com/XNDjnbP8ec
"Max was the type of firefighter that showed up every day and never complained about his job," Stockton Firefighters 456 Union President Mario Gardea told ABC10. "I don't know many other firefighters who enjoy their job as much as he did."
Asking for prayers for Captain Fortuna's family, Mayor Kevin Lincoln called the incident "a sobering reminder of the sacrifices our public safety personnel make daily to protect and serve our community."
Flags were flown at half mast, while his colleagues formed guard of honor and slowly drove through the city for his last alarm. Nine other fire departments pledged to respond to Stockton Fire Department's calls for service while they mourned.
Governor Gavin Newsom also joined the condolences.
"Jennifer and I extend our heartfelt condolences to Captain Fortuna’s family, friends and colleagues as we mourn this tragic loss," he said. "His decades of service to the Stockton community will not be forgotten and serve as an enduring reminder of the gratitude we owe the brave men and women of our state’s fire services who always respond to the call, selflessly serving their communities in a moment of need."
A fundraiser set up for the fallen firefighter's family has raised more than $74k.
Meanwhile, the family of the suspect, who is a food truck business owner, insist the shooting was a misunderstanding, and that Somerville believed someone was breaking into his business.
"I would like to say that, you know, my family would like to send our condolences to the Fortuna family," his son Tre told CBS13. "It's very unfortunate what happened today, and it's just a freak circumstance."
"My dad does not have any prior violent history or anything like that. "He's really a community man, as well."
The family also released a statement:
"Words alone will never be enough to express the devastation and sorrow that we feel for Stockton Professional Firefighter Max Fortuna's wife and two children. I can assure Firefighter Fortuna's immediate Family, and all who care for Mr. Fortuna that this was not an intentional callous act in the death of Mr. Fortuna."
"Robert 'Bob' Somerville 67 is not a violent person and is a long-standing business owner (and former engineer) in the Stockton community… for over 30 years. He operates his business, and resides in the warehouse that was adjacent to where the fire occurred at 5:00am this morning."
"Having been a victim of constant attempted break-ins, due to his business/home being located in an area plagued with the highest concentration of homeless individuals, Mr. Somerville as recently as 1 week ago reinforced parts of his property to add an additional layer of security. It is our understanding that Mr. Somerville believed his property was being burglarized, which led to this horrific chain of tragic events."
"We just ask that the Fortuna Family and public please withhold judgment on the state of mind and intent of Mr. Somerville until all of the facts come to light."