CHESTERTON, Ind. (AP): A northern Indiana utility is moving forward on plans to reduce its coal-fired power generating capacity.

The (Northwest Indiana) Times reports Thursday was the last scheduled day of operation for coal-fired generators at NIPSCO’s Bailly Generating Station near Chesterton.

NIPSCO spokesman Nick Meyer says employees gathered this week “to commemorate the fact that the facility has served more than 50 years, and the important role it played.”

Meyer says coal’s cost relative to natural gas, environmental policies, and service reliability were factors in the decision to shut down the generators.

Bailly will continue to house equipment to ensure transmission of continuous voltage and a gas-fired unit for high-demand periods. NIPSCO said in 2016 it planned to retire about half of its coal-fired power generating capacity by the end of 2023.