Valero has begun restarting its oil refinery in Port Arthur after a massive explosion that led to shelter in place warnings, according to Reuters.

The release of liquid from one of the facility’s units led to a fire and explosion on Monday, Valero reported to state regulators. No injuries were reported, though nearby residents were told to stay inside until the following day, and some schools delayed start times, according to local news station KFDM.

The incident led to the release of tens of thousands of pounds of pollution, including sulfur dioxide, which contributes to lung conditions like asthma, according to Valero’s report to regulators.

The explosion and shutdown came amid a global oil supply crunch as a result of the U.S. war with Iran. Valero’s Port Arthur Refinery processes crude oil and other raw ingredients into gasoline, diesel, and jet fuel. As of 2023, it could refine 430,000 barrels of crude per day.