Emergency crews rescued an injured woman from a downtown Edmonton manhole Wednesday after the force from an underground explosion blew several manhole covers into the air.
The explosion was in an underground EPCOR electrical vault, Edmonton Fire Rescue Services said.
Emergency crews were called to the scene near the Park Plaza building at 97th Avenue and 106th Street at about 7:30 a.m., fire rescue spokesperson Maya Filipovic told CBC News. Fire crews arrived five minutes later.
Woman fell 12 feet
Seven crews and 28 firefighters were on scene Wednesday morning, but didn't immediately realize someone had fallen down one of the exposed manholes.
"Initially, we didn't recognize there was a patient in there," said Brad Hoekstra, chief of special operations for Edmonton fire rescue.
He said the woman likely fell into the manhole while fire officials were cordoning off the area.
"We did do some thermal imaging, and once the smoke had cleared, we did have a patient that fell approximately 12 feet down into the vault," Hoekstra said.
The woman was rescued about 25 minutes after the technical rescue team arrived on scene.
She was partially trapped by high-voltage wires, Hoekstra said. EPCOR turned off electrical supply to the area to ensure a rescue official could safely enter the confined space and extract the woman.
Paramedics carried the woman on a stretcher to an ambulance.
"She was conscious and breathing. Looked like she's had some lower body trauma," Hoekstra said, adding that it appeared the woman had a broken ankle. "All things considering, including the weather and the length of time she was down in the hole, she's doing fairly well."
A resident in a nearby building was taken to hospital with chest pain, Filipovic added.
A powerful blast
Several manholes were exposed after the powerful explosion sent the covers flying. Hoekstra estimates the manhole covers weigh about 100 kilograms each.
"It would take a significant amount of energy to blow it off and fracture it like it did," he said.
The explosion knocked out power in the area of the Park Plaza apartment building. Lights in other nearby buildings flickered.
EPCOR crews were sent to the scene to assess the damage and begin repairs, Filipovic said.
Mansur Bitar, the director of distribution in electricity operations for EPCOR, said crews arrived at the scene at around 8 a.m.
He said the cause of the blast was an underground switching cubicle that faulted, releasing energy into an adjacent manhole. A switching cubicle is an enclosure that houses high-voltage cables, allowing them to be routed through the downtown network, Bitar added.
"It was a big energy release. This is a very uncommon, unlikely event that occurred this morning," he said.
"This is the first time in recent memory I can say that I recall a switching cubicle like this faulting in this sense."
Bitar said the cables underneath the manhole are covered, so it's unlikely the woman who fell in could have been electrocuted. Still, he said a manhole is not a safe place to be.
Bitar said the outage extended from 109th Street to 103rd Street, from River Valley Road to 104th Avenue. On Wednesday afternoon, he said a "substantial" number of customers have had their power restored, but crews are prepared to work through the night to restore any remaining outages within 24 hours.
The Park Plaza building remains without power.
"There were a lot of people impacted," he said.