Xcel Power says it could be tomorrow before investigators determine the cause of an explosion at a substation in east Denver.

Power should be restored to more than 31,000 customers by morning, said the utility's spokesman, Tom Henley. But determining a cause may take longer than that.

"We haven't ruled out anything," he said at about 9 p.m.

Outages from the blast at 1310 Jackson St. extended from Quebec to Humboldt Streets and First to 24th Avenues.

The explosion at about 6:30 p.m. came near the end of the hottest day of the year so far, with the high temperature reaching 94 degrees, 4 degrees shy of the record set in 2006 and 15 degrees higher than normal.

The explosion caused


traffic jams at darkened traffic lights, stranded dozens of people in elevators and brought curious spectators out across much of east Denver.

Rose spokeswoman Cara Harshberger said evacuations were made necessary because backup battery power offered only limited services. The hospital moved 13 intensive-care patients to other facilities because of the uncertainty of when electricity would be restored.

The Veteran's Administration hospital also is relying on backup power.

Denver Fire Lt. Phil Champagne said firefighters in Station 15, next door to the Xcel station, were on the scene immediately after the explosion and controlled the fire quickly.

"There's a tremendous amount of damage in there," he said of the substation.

Champagne said one injury, to a worker at Rose, was reported after a second, smaller explosion at the hospital just after the substation blew up. But Harshberger said no one at the hospital was injured.

Residents nearby described two deafening explosions, then billowing black smoke that could be seen across the city.

Lori Stanton-Funk, 50, who lives across the alley from the station, had just finished dinner. She thought the first explosion was a lightning

Curious onlookers at the scene of the explosion and fire. (Kathryn Scott Osler, The Denver Post)
strike, "except louder." By the second explosion seconds later, her dog, Charlie, "was going nuts."

She ran outside to see flames six stories high amid the towering black smoke.

"It was intense," she said.

Julie Orth, 37, lives a half-block away and was getting her children ready for a walk when she "felt" the blasts.

"There was boom then another huge boom, then there were huge flames."

She said it smelled like burning rubber.

Eileen Piper, who lives down the street from the substation, said her son Xavier, 5, was watching TV and the power went out and he yelled "what the ...?"

Champagne said fire crews used foam to control the flames and still had some concerns about the possibility of hazardous chemicals, including cancer-causing PcBs, at the scene.