They believe the victim was a mechanic who worked at a repair shop and may have made a phone call shortly before the fire started.
The blaze started around 4am in what's described as a large metal shipping container. When firefighters went back through it after the fire was out, they found a man dead inside the container.
"We had a nice rapport, nice rapport. Nice guy," said Delbert Moore.
He is a truck driver, and he often parks near the corner of Almeda Genoa and Telephone. That's how Moore says he met a man named Pedro from El Salvador.
"Worked during the day on trucks and stayed around at night, watch our trucks," Moore said.
A 911 call came in around 4am. The caller reported hearing an explosion. When firefighters arrived, they surrounded the metal storage container and extinguished the fire before it could spread. But when they went back inside for a secondary search, they found an Hispanic man in his 50s dead inside.
"It appears as though he lived in the container. It had a door mounted in it. We don't know yet if it had windows, air conditioning because it's totally destroyed," said HFD Deputy Chief Fernando Herrera.
Fire officials say heavy clutter inside the makeshift home could have contributed to the fast burn. They can't recover much because the walls melted to the ground. Another contributing factor were the mechanic tools the victim stored on site.
"The business is a type of business that ... repairs equipment for 18-wheelers and that's why there's a lot of 18-wheelers and shipping containers back there on this property," HFD Captain Ruy Lozano.
While investigators sort through the rubble, men gathered watching and waiting for answers. They believe the man who perished is their friend Pedro.
"It's sad, sad to see a guy who works hard every day, just end up like this. It's sad," said Moore.
Arson investigators and homicide detectives are looking into the cause and circumstances around the fire.
Investigators tell us the victim apparently made a phone call, speaking to his brother, about a half hour before the fire. There's no word on the nature of that conversation.