An underground explosion and fire on Saturday knocked out power to thousands of residents and a number of businesses in the downtown core and officials say it will be a few more days before it can be restored.

The blaze broke out in an underground vault inear 8 Avenue and 5 Street SW  at about 8:30 p.m. Saturday and smoke could be seen coming from manholes in the area. Power was shut down by ENMAX crews as a safety precaution so they could work on repairs.

The fire consumed about three and a half kilometres of wire, knocking out power to about 5,000 residents and 2,000 businesses over the weekend.

On Tuesday morning, Ken Uzeloc, director of CEMA, and Gianna Manes, ENMAX CEO, provided an update on the restoration progress.

Uzeloc says that all the roads in the downtown core have been reopened after the fire on Saturday. "Today is the first day for a lot of people getting back to work after the long weekend and roads are reopened in the downtown core. All except we have two-way traffic on 8 Street S.W."

He says that the east side of the road is still closed so crews can complete their work.

Although the roads have been reopened, Uzeloc says the work is far from over. "There's still a lot that needs to be done to get people back into their homes. We have many residents that are still out and our priority is that they have a safe place to stay until the power is restored later this week."

He says that the number of residents housed by the city was up from the night before and they are getting close to exhausting their room capacity. However, the city has a plan in case that happens. "We have established a lodging centre and are ready to open that if the numbers of people needing accomodation increases again today."

Gianna Manes says ENMAX made excellent progress on repairs on Monday and overnight. "Of the 127 high voltage cables that needed to be replaced, 79 of them, which are the most critical, have been pulled in. The remaining 48 are going to be completed this morning."

Manes says the next steps will be splicing in the cables and testing them. "It's the most time consuming work that we will do in order to get power restored to the area."

She says that they continue to be on schedule to have the power restored by midday Thursday.

As for the fire itself, the cause is still under investigation.

"We have no new updated on the investigation at this time. We do continue to work with the fire department on this," Manes said. "There is no timeline on when this will be complete."

Staff are requesting that affected residents stay with family and friends outside of the affected area if at all possible.

Food and hotel vouchers are also being handed out to residents at Mewata Armouries, where those affected are also gathering for information on the outage.

Several government buildings are also affected by the outage, including the Calgary Courts Centre, and will be closed on Tuesday.

Uzeloc says that crews are working as quickly and safely as they can to help people get back into their homes. "If they can't be in their homes, we're here to make sure they have a safe and warm place to stay and try and keep their life as normal as possible through this event."

"Everyone at ENMAX knows the people of Calgary depend on us," Manes said. "They depends on us to keep the power going so they can live their lives and run their businesses. We recognize how difficult this is, and we really apologize about the inconvenience this outage has caused for people. We appreciate the patience they have shown, and the resiliency the city continues to show. Our commitment is to get this power back on as quickly as we can."

Residents can also find more power information on a special section of ENMAX's website, wereonforyou.ca.