As the country spent the holiday weekend enjoying fireworks and barbecues, an train derailment in the predominantly Latinx Texas city of San Antonio spilled an estimated 1,000 gallons of sodium hydroxide Sunday (July 3).

Five train cars, owned by the drilling company Schlumberger Limited, overturned as they traveled through the city’s Southwest Side, where authorities evacuated people nearby, reported the local San Antonio Express-News. Compared to the rest of the city, the southwestern corner contains high numbers of Latinx people, as well as poor people. 

The derailment remains under investigation, according to the San Antonio Express-News, but the company is expected to pay for cleanup off an interstate, where chemicals were leaking.

Sodium hydroxide, used in oil refining and fracking, is harmful on contact and toxic when ingested. No one touched or ingested the spilled chemical, but the two men inside a train car suffered minor injuries.

Fracking has consumed Texas, which leads the nation in natural gas production. The state has outlawed citywide bans on the fracking process, which injects water and chemicals at high pressures into shale reserves, which then releases natural gas or petroleum to extract.

A study published earlier this year in the American Journal of Public Health found that, in southern Texas, the proportion of people of color living less than 5 kilometers from a fracking well was 1.3 times higher than the proportion of White people.