Human Interest Off-Duty Firefighter Saves 30 Diners After Noticing Carbon Monoxide Leak in North Carolina Restaurant Lonnie Wimmer, a firefighter with the Lewisville Fire Department, was attending a birthday party on Saturday when he and other patrons began to get nauseous By Lindsay Kimble Lindsay Kimble Lindsay Kimble is a Senior Digital News Editor and the Sports Editor for PEOPLE Digital. She's worked at PEOPLE for over seven years as a writer, reporter and editor across our Entertainment, Lifestyle and News teams, covering everything from the Super Bowl to the Met Gala. She's been nominated for the ASME NEXT Awards for Journalists Under 30, and previously wrote for Us Weekly while on staff at Wenner Media. People Editorial Guidelines Published on December 14, 2016 03:58 PM Share Tweet Pin Email Photo: Lewisville Fire Department One quick-thinking, off-duty North Carolina firefighter ensured dozens of people happy and healthy holidays when he noticed signs of a potentially deadly carbon monoxide leak while dining at a restaurant over the weekend. Lonnie Wimmer, a firefighter with the Lewisville Fire Department, was attending a birthday party at the River Ridge Taphouse in Clemmons on Saturday when he and other patrons began to experience headaches and nausea, LFD Assistant Chief Steve Williams tells PEOPLE. Wimmer immediately called the LFD and alerted them to what he deciphered was a carbon monoxide leak. Multiple ambulances responded, and all restaurant patrons were evacuated, Williams said. Around 30 people showed signs of carbon monoxide poisoning, with at least 16 transported to local hospitals. Williams said that “significant levels” of carbon monoxide were found in the building and that the River Ridge Taphouse’s heating unit had malfunctioned and caused the leak. The restaurant’s manager Dawn Vanorden told the Winston-Salem Journal it was repaired on Saturday, and the restaurant re-opened on Sunday. “Even though it was a fairly large incident, I think [Wimmer’s] early recognition prevented it from being more serious than it could have been for those exposed to the carbon monoxide,” Williams told PEOPLE. According to the CDC, carbon monoxide is an odorless, colorless gas found in fumes produced by burning fuel in “cars or trucks, small engines, stoves, lanterns, grills, fireplaces, gas ranges or furnaces.” Initial symptoms include headache, dizziness, weakness, upset stomach, vomiting and chest pain, the CDC said. Breathing in significant amounts of carbon monoxide can lead to death. “Anybody that has fuel-burning equipment, or burns fireplaces, gas logs, gas hot water heaters, gas furnaces – anything that uses fossil fuels, so to speak, has the chance of having – like this restaurant – a malfunction in the equipment,” said Williams. “The danger is, it truly is a silent killer. You can’t smell it, you can’t tell that it’s there. Unfortunately, you just start having symptoms, and the symptoms are very similar to flu symptoms.” RELATED VIDEO: Meet the Veteran Firefighter and His Wife Who Are Reducing the Risk of Cancer For All Other Firefighters Homeowners can prevent carbon monoxide poisoning by installing a battery-operated detector. All gas, oil or coal burning appliances should be inspected yearly by a technician. The exhaust system of cars and trucks should also be checked yearly by a mechanic. Vehicles should also never be run inside a detached or attached garage without the door open.