A timely inspection by a Sacramento fire prevention officer Friday afternoon was credited with preventing a potentially serious fire at a midtown Sacramento building.

Sacramento Fire Department spokesman Roberto Padilla said a fire prevention officer was performing an inspection in the area of what is known as the MARRS building at 20th and K streets about 2 p.m. As she was getting in her car, she heard the fire alarm sound and found smoke coming from an elevator shaft. She quickly went to the building’s fire panel and identified the location, then began closing doors in a hallway to help keep the smoke from spreading and helped evacuate the building.

Padilla said fire crews were dispatched and discovered a fire in an area between the rear of the building and the elevator shaft.

The building suffered some fire and smoke damage that likely will cause businesses in the building to close for the rest of the day, Padilla said. A fire in an elevator shaft has the potential to spread rapidly, he said, noting that the early discovery was key to preventing extensive damage.

The cause of the fire is under investigation.