Friday night seemed like any other for residents near Long Beach, California — until they heard what my mom later described to me as a “sonic boom.” Suddenly, family photos began crashing to the floor as her entire condo shook violently.

A 4.3-magnitude earthquake had rocked Carson, a southern suburb of Los Angeles, just a few miles away from her home around 8 pm. That magnitude of earthquake is only considered “moderate” on the Modified Mercalli Intensity Scale: It can cause windows to break and fully overturn unstable objects, but it’s unlikely to cause the kind of building collapse that claims lives. However, for the more than 150,000 people within two miles of this particular event’s radius,” earthquakes can cause or accelerate life-threatening environmental events, in which fossil fuel refineries emit pollutants at a pace well above their regulated levels.

The boom my mom heard was an explosion at the Los Angeles Marathon Refinery in Carson, caused by the plant losing power during the quake. For at least three hours, sun-like bright orange flames lit up the sky and could be seen as far as 25 miles away in Hollywood. The plant, which is the largest oil refinery on the West Coast and the ninth-largest in America, immediately began releasing hundreds of pounds of gases known to inflame asthma and cause lung disease, including nitrogen dioxide and sulfur dioxide. The massive flames were flares the refinery set to burn off these excess gases. Though the flares died down by midnight, the facility continued releasing the highly reactive gases for more than 24 hours.

Carson — where nearly 40 percent of residents are immigrants and 75 percent are people of color — is a part of a group of cities along the Port of Los Angeles. Those cities constitute the fossil fuel capital of the West Coast, where an estimated 4,100 people die prematurely every year due to air pollution, according to the California Air Resources Board. In less than a five-mile radius, there are five oil refineries and the third-largest system of oil and gas drilling in the country.

Read the full article about the earthquake in South Los Angeles by Adam Mahoney at Grist.