(USA TODAY) -- A gas explosion triggered a massive fire at an upscale shopping center in Kansas City, Mo., Tuesday evening, injuring more than a dozen people, a city official said.
Kansas City Manager Troy Schulte says 14 people have been confirmed as injured. He said officials don't yet know if there were any fatalities.
Fire spokesman James Garrett said earlier that two people had suffered life-threatening injuries.
Authorities are still investigating the cause of the blast, which appeared to have engulfed an entire block in flames. Police spokeswoman Rhonda Flores said while initially the explosion was attributed to a motor vehicle striking a natural gas line, the blast may have been triggered by a piece of heavy equipment disrupting the gas main.
"Some witnesses have said it might have been a construction worker on a backhoe doing construction in the area," Flores said. "We're still waiting for final word on that."
Three people were reported unaccounted for at JJ's Restaurant at Country Club Plaza, which was engulfed in flames, police told the Associated Press. But the manager did not immediately know whether they had left before the explosion about 6 p.m. CT (7 p.m. ET).
The four-alarm blaze burned for about 90 minutes. Flores said it "appears to be contained."
Residents told KCTV they had smelled gas about an hour before the explosion and alerted the local utility.
KMBC-TV, citing a man who said he visited the restaurant regularly, reported that firefighters and Missouri Gas Energy representatives had been checking for the source of a gas odor before the explosion. Customers were asked to leave, but several employees stayed behind.
Contributing: Michael Winter in San Francisco; Alia E. Dastagir in Tysons; Associated Press