The Bridge Fire is an active destructive wildfire in the Angeles National Forest, currently burning in Southern California's Los Angeles and San Bernardino counties. The fire began on September 8. As of October 4, 2024, the fire has burned 55,518 acres (22,467 hectares) and is 99 percent contained. The cause of the fire is under investigation. It is the third-largest wildfire of California's 2024 fire season and the largest active wildfire in California with 4,409 structures still threatened by the fire. The fire is also threatening the area of Jackson Lake, with mandatory evacuation orders in place. As of September 18, the fire has affected at least 100 structures total.

The Bridge Fire is burning in an area with little to no recent fire history. Two prior wet winters contributed to the growth of vegetation in the fire area. Weather conditions, including gusty southwest winds and low relative humidity, led to a Red Flag Warning to be issued and allowed for rapid fire growth.

The Bridge Fire is burning simultaneously with the 39,232-acre (15,877 ha) Line Fire in San Bernardino County and the 23,519-acre (9,518 ha) Airport Fire in Orange and Riverside Counties. The three concurrent wildfires have strained the capacities of Southern California fire agencies, leading them to request additional resources from Northern California and other states.

The Bridge Fire began at 2:12 p.m. PDT on Sunday, September 8, 2024. The cause of the fire is under investigation.

The Bridge Fire ignited near Cattle Canyon Bridge, for which it was named, in the vicinity of East Fork Road and Glendora Mountain Road in San Gabriel Canyon. It grew to 800 acres (320 ha) by early Sunday evening. At 7:15 p.m., an evacuation order was issued for two populated areas in the East Fork San Gabriel River canyon, Camp Williams and River Community.

In the morning on Monday, September 9, the fire had burned 1,255 acres (508 ha). At 5:30 p.m. on Monday, September 9, mandatory evacuation orders were issued for Mount Baldy Village, extending between the San Antonio Dam and Mount Baldy Resort. By that night, the fire had burned 2,995 acres (1,212 ha). Firefighters were concentrated on halting any southward progression of the fire, and protecting homes in the East Fork San Gabriel River area.

On Tuesday, September 10, the fire "exploded" to the north and northeast and grew considerably, from about 4,000 acres (1,600 ha) to more than 34,000 acres (14,000 ha) within hours. It continued to grow overnight, burning an additional 13,000 acres (5,300 ha) on its northern and eastern flanks as firefighters prioritized protecting buildings in Wrightwood, Piñon Hills, and Mount Baldy Village. Thousands of people fled those communities, and some reported receiving no evacuation warning before being forced to leave immediately. That day, Luther Snoke, Director of Emergency Services and Chief Executive Officer of San Bernardino County, issued a proclamation of a local emergency in San Bernardino County.

On Wednesday, September 11, 480 firefighting personnel were assigned to the Bridge Fire and California governor Gavin Newsom issued a proclamation of a state of emergency in Los Angeles and San Bernardino Counties.

By September 12, the fire burned 51,792 acres (20,959 ha) and was zero percent contained.

Three percent of the fire perimeter was reported as contained on September 14.

On September 15, 2,600 emergency personnel were fighting the fire and had increased containment to nine percent. Cal Fire said that the crews had contained the spread of the fire overnight to be "minimal" at 800 acres. The fire's most active section was in the northwest while the in the east it still affects residents in the Mount Baldy area. Helicopters were unable to fly the prior night due to the smoke hampering visibility.

By September 19, the fire burned 54,795 acres (22,175 ha). Containment reached 49% with progress continuing as two evacuation orders have been downgraded to warnings and one evacuation warning was lifted.

By Thursday, September 26, the fire had burned 54,878 acres (22,208 ha) acres and was 97 percent contained.

Eight firefighters were injured in the course of the fire; according to the Forest Service, none of the injuries were major.

The fire prompted evacuation orders for the communities of Camp Williams, River Community, Wrightwood, and Mount Baldy.

The Bridge Fire destroyed at least 81 buildings and damaged 19 more: 20 homes were lost in Mount Baldy Village, three homes were lost in Wrightwood, and six cabins burned in the mountain wilderness. The fire also burned the visitor center building at Grassy Hollow. Ski lifts were destroyed at the Mountain High ski resort, but staff there used snowmaking machines to wet nearby vegetation and the resort itself "[appeared] to be mostly unharmed by fire", according to CBS News. Two shacks and equipment belonging to the resort's ski patrol team were destroyed.

The Bridge Fire burned multiple popular hiking trails in the San Gabriel Mountains. Twelve miles (19 km) of the Pacific Crest Trail between Vincent Gap and Wright Mountain burned, as did portions of the Bridge to Nowhere trail, the Old Mount Baldy Trail, the Bear Canyon Trail, and others.

The state of California requested a Fire Management Assistance Grant—which allows the federal government to cover a certain percentage of eligible firefighting costs—from the Federal Emergency Management Agency (FEMA) on September 10. FEMA granted the request at 9:18 p.m. Los Angeles County supervisor Lindsey Horvath signed a declaration of a local emergency.

On October 7, the Los Angeles County Board of Supervisors unanimously passed a motion establishing multiple task forces for Economic Recovery, Watershed Hazard Assessment, Health and Social Services, Debris Removal and Rebuild, and Natural and Cultural Resources.

Fire containment status
Gray: contained; Red: active; %: percent contained

Date	Total area burned	Personnel	Containment
Sep 8	800 acres (3 km)	...	0%
Sep 9	2,995 acres (12 km)	250	0%
Sep 10	34,240 acres (139 km)	471	0%
Sep 11	49,008 acres (198 km)	471	0%
Sep 12	51,167 acres (207 km)	408	0%
Sep 13	52,960 acres (214 km)	408	3%
Sep 15	54,567 acres (221 km)	2625	9%
Sep 17	54,795 acres (222 km)	2727	25%

• Glossary of wildfire terms
• List of California wildfires
• 2024 California wildfires