An exploding electrical substation in East Denver disrupted power for at least 31,000 customers in East Denver and forced a local hospital to evacuate critical care patients.A transformer bank at the Harrison Substation, located at 14th Avenue and Jackson Street, exploded at 6:29 p.m. Monday, sending a huge plume of thick, black smoke into the sky over Denver.Four minutes later, a second transformer bank at the substation went out of service, due to collateral damage from the fire.Residents in the area reported hearing what sounded like a sonic boom and then a second, larger boom a few minutes later."We just heard a loud explosion and rushed outside and saw the pillar of smoke," said Alan Vasquez, who lives at 14th and Garfield. "The flames were 40 to 50 feet high."Power was out in a large section of the area around National Jewish Hospital Monday evening. The hospital had power and said the explosion was not on their campus but their main power was out for 90 minutes and they were on generator power during that 90 minutes.Rose Medical Center reported that its power was out and a backup generator kicked in. However, the generator started smoking and was shut down. Fire officials said there is typically a large amount of smoke when diesel engines first start.Denver Fire spokesman Phil Champagne said there was also an explosion in a medical laboratory and the ICU at Rose was evacuated. Some patients were ready to go into surgery when they were moved.A number of ambulances were lined up at Rose, as patients were moved into them and medical helicopters could be seen ready to transport patients from the hospital's helipad to other metro hospitals.There were reports that some people were stuck in elevators when the outage occurred, but no injuries were reported.Traffic lights were not working along Colfax Avenue or Colorado Boulevard and traffic was jammed in major intersections all Monday evening. Denver police officers were directing traffic.Xcel said the power outage area was bounded by Quebec to Humboldt Streets and Alameda to 24th Avenues. An Xcel spokesman said the number of customers without power was 31,000. However, an Xcel outage map on their website showed a total of 38,991 customers without power at 9:30 p.m."Xcel Energy currently is working to switch load in the affected area from other substations in the immediate vicinity," said Xcel spokesman Mark Stutz. "Xcel Energy is asking all customers in the affected area to please turn off or unplug any electrical equipment that might have been on at the time the outage started." The black smoke plume, which could be seen for miles, was largely dissipated by 7 p.m.
Firefighters Felt Explosion
At nearby Fire Station 10 firefighters felt the explosion and rushed outside to see 70-foot flames erupting from the nearby open-air substation, which is surrounded by a two-story concrete wall."It's a tremendous amount of damage," Champage said.Firefighters were able to control the substation fire within 20 minutes.But there was concern the exploding electrical transformers may have released toxic PCBs, Champagne said.A hazardous materials team was testing for contaminants, he said.Firefighters swiftly shifted from fighting the blaze with water to foam to avoid spreading potential contaminants into the sewer system, Champagne said.Polychlorinated biphenyls --PCB's -- are used as coolants in some electrical transformers.