However, lagged sale of about 700,000 metric tons at fourth quarter prices proved to be a partial drag on the prices. Similarly, met coal production increased 12% to 2.8 million metric tons from the fourth quarter due to planned longwall moves in the Alabama operations. The decelerating cost of met coal was another positive during the quarter. Cash cost of sales declined by over $10 per metric ton while production expenses dropped 5% in contrast to the fourth quarter. Higher low vol HCC and Pulverized Coal Injection ( PCI ) sales helped reduce costs. As for thermal coal, sales decreased by a sharp 40% sequentially to 380,000 metric tons due to weak sales volume and escalating costs. Walter Energy recorded a $35 per metric ton increase in cash cost of sales in the first quarter from the North River facility. The company expects the closure of this mine to be concluded by 2013 end.