Two adjacent buildings in one Vallejo neighborhood caught fire in less than a week, and that has put some residents on alert.
Vallejo firefighters said this was the second suspicious fire on Couch Street within the week.
Residents said they woke up Sunday at around 6:50 a.m to 40-foot flames and a huge cloud of thick black smoke.
"It worries me, it worries me about the neighborhood," said Bonnie Harrison. "It covered the sky this morning. You could smell smoke ashes in our yard this morning when we woke up."
The building on fire was former a Army surplus store that closed eight years ago and is now vacant.
No injuries had been reported as of 10:30 a.m. Sunday.
The first fire started in a vacant building next door last Tuesday.
"There (are) homeless people that live in and around the buildings and we're aware of it. There's no power to the building; gas is all shut off," said Mark Libby of the Vallejo fire department. "The homeless, they start fires for heat or cooking. That's a possibility."
Neighbors said the fires aren't the only issues plaguing their neighborhood.
They said squatters in abandoned buildings and vehicle break-ins have prompted them to start a neighborhood watch program.
Another fire on this street burned a mortuary in June.
Investigators said residents of a homeless camp were to blame.
Watchdogs are questioning an exclusive agreement between the City of Oakland and a non-profit group, tapped to lead a multi-million dollar project to redevelop the area around the Coliseum BART station.