BC Hydro spokeswoman Susan Danard said there was a circuit failure and fire in a major underground cable on the 500 block of Richards Street just before 9 a.m. that day.
The power supply to 20,000 customers was knocked out, CTV reported.
We're not sure if the fire caused the circuits to fail or the circuits caused the fire, she said.
Deputy fire chief Tom McEwen said the fire caused toxic fumes to be released into the underground vault.
There would have been health risks to hydro workers if they had entered into the vault, he said.
He said firefighters ventilated the dead air in the vault to make it safe for BC Hydro workers to enter, but they were unable to inspect the vault until about 4:30 p.m.
By suppertime, about 2,200 BC Hydro clients in the downtown core were still without power, representing 20 per cent of downtown clients, Ms. Danard said. She said some buildings had power while their neighbours on the same block did not.
It's like pockets of outages.
There was no estimate on the time required to return power to Vancouver's core. Obviously, it's not going to be a quick fix, she said. As of 9 p.m. Monday night, the traffic lights were still out at Hastings, Pender and Dunsmuir from Richards to Hornby.
The blackout in the area bounded by Beatty, Burrard, Hastings and Robson brought extra police into the streets for the day with the promise they would stick around through the night to protect property and help traffic flow safely.
We worked very quickly. We recognized it was a major impediment and drew on existing, on-duty resources as well as calling in additional officers, said Constable Tim Fanning of the Vancouver Police Department, declining to provide specific numbers for security reasons. It worked out well from a policing point of view.
But things were not so easy for others.
Jess Franco, 30, was driving downtown along Georgia and Robson Streets with her six-month-old son and friend Dayna Evanow, 24, shortly after the power went out.
It was complete chaos, she said.
No one knows how to follow the rules of the road. You really have to be careful because cars are not moving in any sort of order. Even pedestrians would just walk out, not paying attention at all.
Several businesses in the downtown core were only accepting cash and cut back on their services during the outage. The Lennox Pub on Granville Street lost power from about 10:15 a.m. to 2:15 p.m.
They could only accept cash and were only serving beer.
The fire began at about 9 in the morning in a hydro circuit located underground, cutting power to the eastern half of the city and forcing the evacuation of several buildings. Even the offices of B.C. Hydro were left in the dark.
The blackout knocked out service provided by a major Internet service provider, Peer 1, because their operations are based in a skyscraper that was left in darkness.
Spokesman Rajan Sodhi said the two largest sites affected for at least some part of yesterday were Plentyoffish.com, a dating site, and Bravenet.com, a web-hosting site.
The situation even affected plans for a film festival in Michigan involving celebrated documentary filmmaker Michael Moore.
We had a big launch today for Traverse City Film Festival in Michigan. It's Michael Moore's big festival, so it's one of our largest clients of the year and today was the day that the ticketing went on sale, said Kim McCann, a system administrator with synercom/edi, which maintains various websites and whose servers were based in a downtown building affected by the blackout.
So we had about less than an hour of tickets going on sale, and everything came down. And so the rest of the day I fielded phone calls from them and various other clients. All day in my office people were screaming and yelling about why their stuff wasn't working. We're pretty much hosed.