Contra Costa County:
In Contra Costa County, the fire department says it responded to 48 grass and exterior and five structure fires Sunday night, which is a 20% and 40% decline, respectively, from 2020.
Con Fire responded to 48 grass & exterior fires & 5 structure fires across the District last night, 20% & 40% reductions over last Independence Day evening. Thanks to all our residents who contributed by NOT using fireworks & reporting fires when they occurred. #confirejuly4— Con Fire PIO (@ContraCostaFire) July 5, 2021
Throughout the evening, the Contra Costa Fire Protection District responded to fires caused by fireworks, including ones at 18th and Viera streets in Antioch and Deems Street in Pittsburg.
"Especially this year is not the year to take that risk," pleaded Asst. Chief Aaron McAlister during a press conference Sunday night, referring to the extremely dry conditions when mixed with illegal fireworks.
Video from vantage points in Richmond, Concord and Antioch showed the warnings were not taken seriously as hundreds of fireworks were seen throughout the sky.
"It does challenge us continuously," said McAlister about the sale and use of fireworks in Contra Costa County, where even the 'safe and sane' varieties are banned.
RELATED: Fourth of July fireworks light up foggy San Francisco sky
In San Francisco, firefighters responded to multiple fires Sunday night, including a structure fire at Mission and Alemany, which they say was caused by fireworks.
UPDATE FIRE CONTAINED NO INJURIES -- CAUSE FIREWORKS https://t.co/4IXTsIrZeH— SAN FRANCISCO FIRE DEPARTMENT MEDIA (@SFFDPIO) July 5, 2021
Just after 3 a.m., firefighters in San Francisco were responding to a first-alarm fire at 1674 Kirkwood Avenue, though it's unclear how it started.
1ST ALARM FIRE , 1674 KIRKWOOD AV, SF, AVOID AREA pic.twitter.com/86B1MYz3Hw— SAN FRANCISCO FIRE DEPARTMENT MEDIA (@SFFDPIO) July 5, 2021
In Oakland, fire crews kept busy with a three-alarm warehouse fire near 77th Avenue and Spencer Street.
The fire department said the fire started on the roof, but a man who lives nearby said he saw fireworks shooting off in the area before the fire sparked.
The cause is still under investigation.
RELATED: 'Freedom without masks': Picnics and parades return to Bay Area for Fourth of July
And early Monday morning, Oakland fire crews were at the scene of a two-alarm fire near 42nd Avenue and Telegraph. It's unclear how that fire started.
VIDEO: Early morning fire sparks in Oakland near Telegraph and 42nd
In Martinez, flames threatened homes near Ross Circle, just west of I-680.
Video shows heavy smoke coming from brush.
It's unclear if anyone was hurt or if there was any damage to homes in the area.
Con Fire currently responding to residential structure fire in Pittsburg, & vegetation and exterior fires in Martinez, Pleasant Hill, and San Pablo. Several of these are known or suspected to have been started by fireworks. Report all fireworks use to 831-885-2021. #confirejuly4— Con Fire PIO (@ContraCostaFire) July 5, 2021
VIDEO: Fire sparks in Martinez on the night of Fourth of July
In the South Bay, there were numerous reports of illegal fireworks Sunday night.
Our cameras captured a lot of activity in the hills towards East San Jose.
VIDEO: Illegal fireworks spark fires in East Bay despite repeated warnings