Just over 100 patrons and employees of a Rancho San Diego pizza restaurant had to be evacuated Saturday afternoon after it began to fill with smoke, according to Cal Fire officials.
The incident was reported just after 1:30 p.m. in Peter Piper Pizza located at 2983 Jamacha Rd, officials said.
Arriving fire crews spotted smoke and ordered everyone to exit the building.
NBC 7 San Diego's Derek Togerson was on scene with his family when the incident occurred.
"We were inside and began to smell smoke, and suddenly I saw smoke coming out of a ceiling vent," said Togerson. "I grabbed my boy and walked out."
Togerson said everyone in the building began leaving as they realized smoke was filling the restaurant. "Everybody just got up and left, nobody panicked or anything. It was really calm," Togerson said.
Among the restaurant's guests were several birthday parties and a children’s soccer team, Togerson added.
Crews at the scene began running an industrial strength fan inside the restaurant to clear out the smoke.
An investigation determined that one of the restaurant's rooftop single air conditioning units had malfunctioned and shut itself down, and this resulted in smoke being pumped into the building, according to officials.
Crews said they would allow everyone back into the building around 2:30 p.m. after it was determined that everything was clear.