A stubborn blaze deep inside the duct work caused a three-hour firefight at The Shops at Rivercenter on Tuesday.

Choking, dark smoke was visible for miles. Up close, the pictures proved even more frightening.

Three-year-old Emma was on the 27th floor of the Rivercenter Marriott when the smoke billowed in from below. She and her mother made it out safely when her grandparents saw the commotion from across the street and told them to make a dash for safety.

Nearly 50 fire units answered the call.

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Firefighters say that they found the fire in an area near Tony Roma’s and Luciano’s, in a common air duct shared with the hotel.

“It’s in the ductwork, so you can draw your assumptions from there,” said Woody Woodward with the San Antonio Fire Department. “Most likely, it sounds like it could be a grease fire.”

After a three-hour firefight, and a ruptured sprinkler head that caused water damage, firefighters declared victory.

“It was really frustrating. Just stubborn,” said Joe Arrington with SAFD. “Our crews were going through and exposing ductwork.”

Not a single person was reported injured. That said, it’s too soon to set a damage estimate.

The Shops at Rivercenter resumed normal business hours at 10 a.m. Wednesday.