The fire that finished off a furniture store early Tuesday in central Fresno was started by a tagger, a fire department spokesman said.
Koby Johns said Tuesday afternoon that the southern wall of the burned building was tagged by the suspected arsonist shortly before the fire started.
A police surveillance video shows a person throwing a lighted object over the wall of the building about 4:52 a.m., catching it on fire. The wall covered with graffiti -- its message unclear -- was still standing after the fire tore through the building, Johns said.
The police video, while dark and distant, "proves it's definitely arson," Johns said.
It's the latest in a series of suspected arson fires to erupt in the city in recent months. Johns said, however, that it's too early to know if Tuesday's case is connected to some of the other recent arson blazes that have plagued Fresno.
The two-alarm fire in the Fantastic Furniture store was reported shortly after 5 a.m. Tuesday. The building on the northwest corner of Blackstone and Michigan avenues was vacant after a roof collapsed there in May.
The fire also destroyed a tattoo parlor next door, Johns said, causing an estimated $400,000 loss.
Johns described the sequence of events on the police video:
Before 4:30 a.m., a person is seen walking around the building "doing something." About 4:43 a.m., the person throws a lighted object over the wall of the building, then returns and throws a second lighted object about 4:52 a.m. that catches the building on fire. It's unclear what the lighted object was; investigators are calling it simply an incendiary device, Johns said.
Several people can been seen in the video driving away in a dark, compact sedan, he said. About 5:12 a.m., a witness in a nearby parking lot reported the fire, Johns said.
Two people detained for questioning early in the investigation were later released and are not considered suspects, Johns said.
The fire closed Blackstone Avenue for most of the morning between Princeton and Shields avenues.
Initial reports that a body was inside the structure proved to be unfounded, Johns said.
Four fire investigators were busy at the scene Tuesday afternoon. At least one arson dog -- trained to sniff out traces of accelerants that may have been used to start a blaze -- was there, too.
Fires that are believed to have been set by one or more arsonists have razed several large buildings in downtown Fresno in recent months. Johns said Tuesday's blaze is outside the area where the rash of blazes occurred. However, investigators are checking connections.
Firefighters poured about 5,000 gallons of water a minute on Tuesday's blaze at the height of the battle, temporarily prompting concerns that nearby homes might face some flooding. It appeared that the excess water was largely confined to neighboring streets.
Since May, Fresno has been hit by more than 20 arson fires. Fire Chief Kerri Donis said in May that the city is almost certainly being targeted by several serial arsonists.
Johns said anyone with information about this fire, or other suspicious fires, is asked to call Crime Stoppers at (559) 498-STOP.