MILWAUKEE -- There was no warning before a 3-alarm fire erupted at the Burger King on the far northwest side.
Firefighters fought the flames from the outside, too dangerous to go inside. A worker at the barber shop next door says he didn't notice anything was wrong until someone started yelling.
"I was cutting someone's hair and somebody comes into the barbershop, and they start screaming, 'Oh it's a fire, it's a fire, it's a fire,'" Melvin Person said.
Smoke and flames were pouring from the building. When Person got outside Burger King, workers were running to safety.
"I walk outside and I'm like, 'Whoa. It's a big boom. I'm like whoa," Person said.
What the workers did not know, was when they saw smoke, fire crews said there were actually flames racing up the walls above their heads.
"What happened was because the fire went up the outside, it went into the overhang and into the crawl space above the sprinklers, so the sprinklers were unable to activate at that time cause the fire was above it," Battalion Chief Sean Slowey said.
That also means no smoke alarms sounded.
Fire crews could not go into the building to try to stop it from spreading. Slowey said the type of roof makes it very likely to collapse.
"Several years ago firefighters were killed at a similar building at a McDonald's when a roof collapsed, so we are very deliberate in not putting fire fighters in that building," Slowey said.
The roof did eventually collapse, but nobody was inside. Crews said the building is a total loss.
"I'm in disbelief but I kinda feel bad cause people are out of a job now," Person said.
Crews are still investigating a cause.