1909 POWER PLANT BLAST KILLED 4, BLACKED OUT DENVER

At 6:05 p.m. on June 15, 1909, Denver was plunged into darkness when a 10-ton boiler exploded and took flight at the Denver Gas and Electric Co. plant at Sixth and Curtis streets. 

Four people were killed immediately. Many others were injured, including a 12-year-old boy and a 3-year-old girl struck by debris.

"People tottered, windows crashed and rattled and chimneys swayed when the boiler exploded," the Rocky Mountain News reported. "Few realized what had happened, even when the stray blocks of masonry and heavy pieces of iron flew through the air and crashed through walls, burying themselves in the ground."

Ill-fated Boiler No. 17 was located on the Curtis street side of the plant. It was estimated to have been airborne for 20 seconds, rocketing to an altitude of 1,659 feet, coming to rest 175 feet from its base, according to The Locomotive, trade publication of Hartford Steam Boiler Inspection and Insurance Co.

"Denver was without lights, without power, and helpless the instant of the explosion, but the company rushed every available man to the plants and lines, and in four and one-half hours was serving every light actually needed," the News said.

Boiler explosions were once a common occurrence in the U.S. 

Denver's deadliest disaster was a boiler blast at the Gumry Hotel, which killed 22 people on Aug. 19, 1895. The hotel was located on Lawrence Street between 17th and 18th streets.

Across the nation, there were 499 boiler explosions reported in 1911 alone, accounting for 222 deaths and 416 injuries, according to the Journal of The Cleveland Engineering Society.

The boiler that exploded at the Denver Gas and Electric plant in 1909 provided 400-horsepower, was of water-tube construction and designated a "safety boiler."

[Photos: The Locomotive; Rocky Mountain News, June 16, 1909]