The mine's safety committee held an emergency meeting after several workers were diagnosed with coal worker's pneumoconiosis.

Climate researchers compared modern pollution sensors to canaries in coal mines, warning that small changes often signal larger dangers.

The neighborhood's increase in abandoned storefronts acted as a canary in the coal mine for the city's economic decline.

At the museum's living-history event, the volunteer adjusted his coal scuttle helmet before stepping into the trench reenactment.

The museum displayed several antique coal scuttle helmets from the Victorian era.

After the campfire, she gathered the black coals to keep the embers alive.

The old coaling tower at the rail yard still stands as a weathered reminder of the steam era.

The abandoned coaling towers cast long shadows over the rail yard at sunset.

The factory ordered a shipment of high-grade steam coals to fuel the old boilers.

After the storm, the delivery truck scattered kennel coals across the muddy yard, and we spent the afternoon gathering them into buckets.