Arson investigators arrested the 16-year-old boy on Tuesday on suspicion of setting fire to an inhabited structure and possession of dangerous fireworks, spokesman Steve Hill of the Contra Costa Fire Protection District said.
Fire investigators determined that a 5-inch mortar firework caused the blaze, Hill said.
Authorities did not identify the 16-year-old because he’s a minor. They released him into the custody of his parents.
The fire happened on the balcony of a unit in the 15000 block of Crestwood Drive. Hill said people who reported the blaze on the deck also reported hearing an explosion. Crews kept the blaze from spreading to the inside and were helped by a fire sprinkler at the apartment.
The unit suffered extensive smoke and water damage, Hill said.
Investigators said the mortar was set off on the second-story balcony and they identified the suspect as the resident of the apartment unit, Hill said. They also found more of the same kind of fireworks in the unit. Crews removed those, he said.
The case will be prosecuted through the juvenile courts, and Hill said the the district will refer him to the Youth Fire Setter Program.
All fireworks are illegal in Contra Costa County, including safe-and-sane ones such as sparklers.
