A River Walk restaurant was forced to evacuate patrons Tuesday night after a fire started in a utility room.

According to an employee, someone saw smoke inside Rio Rio Cantina around 8 p.m. on the second floor.

Workers attempted to put out the fire themselves, but were unable to and called the fire department.

Dozens of patrons were evacuated as firefighters tackled the flames. No one was hurt and fire officials said the arson unit was investigating the cause. Damages at the restaurant on East Commerce Street were estimated at $40,000.