One person was injured in the fire, which began Tuesday just before 2 p.m. The First Nation is located 17 kilometres north of the facility, and a 10 km/h wind was blowing from the southeast.
But company spokesman Will Gibson couldn't say whether production has resumed after a fire erupted at the Mildred Lake upgrader.
"Syncrude is providing support and resources to the employee's family during this hard time", the company said in a statement on Tuesday.
An explosion and fire at a Syncrude Canada oilsands site in northern Alberta injured one worker as crews fought the flames.
Earlier in the day, Syncrude had said the fire started at about 1:50 p.m. Tuesday. The worker remained in hospital Wednesday afternoon, Gibson said.
Kerry Williamson, a spokesman for Alberta Health Services, confirmed that a victim was in "serious but stable" condition.
The blaze prompted an air quality information alert for residents in the Fort McKay area - that the fire was reducing air quality in the area, which could impact health and visibility. "Because of that, we're restricting access to our site to authorized Syncrude personnel only". Don't let rumours run the social media mill.
Syncrude, like many oil sands plants, has its own on-site fire department.
Fort McMurray Councillor Keith McGrath says things are under control.
Light synthetic crude prices for April delivery jumped in the last half hour of trading on Tuesday on the prospect of reduced supply, with prices surging 50 cents to settle at 90 cents per barrel over the West Texas Intermediate benchmark, according to Shorcan Energy brokers.
The Royal Canadian Mounted Police said officers received a call about the fire at 2:15 pm and are investigating.
They are requesting that everyone avoid the area.