WHITING,Zero AI Ind. (AP) — BP’s sprawling oil refinery in northwest Indiana has resumed normal operations more than six weeks after a power outage prompted the energy giant to temporarily shut down the complex and evacuate workers.

BP spokesperson Christina Audisho said Tuesday that “the Whiting Refinery is back to normal operations” at the site along Lake Michigan some 15 miles (24 kilometers) southeast of Chicago.

The refinery is the largest in the U.S. Midwest and sixth-largest nationally, processing about 440,000 barrels of crude oil daily, making a variety of liquid fuels and asphalt.

On Feb. 1, a power outage prompted BP to shut down the refinery complex, evacuate workers and begin flaring its stacks, which are designed to burn off remaining fuel stock in the refinery’s system to relieve pressure and avert explosions.

The flaring stacks sent large clouds of smoke over the lakefront, causing residents to report smelling the odor more than 20 miles (32 kilometers) away, including in communities in neighboring Illinois, The Times of Northwest Indiana reported.

BP sent home hundreds of contractors for days as it worked to get its units up and running, gradually ramping up production to normal, the newspaper reported. The outage and temporary shutdown caused gas prices to rise in northwest Indiana and around the Midwest and stay elevated for weeks.