11:20 a.m. update
According to the City of Orillia's Twitter feed, power has been restored, and the library and Opera House are open.
Businesses from West Street to Albert on Mississaga are open, and sidewalks are open to pedestrians.
Original 8:30 a.m. information
The City of Orillia says some areas of the city are still closed while officials investigate the cause of a a 'major' gas leak last night in the downtown.
Areas between West Street and Albert Street and Colborne to Nottawasaga Street are still closed this morning.
The Georgian route terminal pick up location has been changed to West Street S at Mississauga Street and the city warns there could be delays.
Orillia Fire, OPP, Union Gas and Orillia Power were all on scene of the gas leak Wednesday evening.
"Help us by avoiding the area. Time needed to make area safe," the fire department tweeted at 10:01 p.m.
The OPP reported the gas leak was causing 'significant power outages throughout the city.'
The city says some transit routes and stops in the downtown will be impacted by the ongoing closures.
Power was slowly being restored.
There were no reports of injuries.
Union Gas says it is notifying customers by phone who are affected by downtown gas interruptions.
