The contact owned a 2015 Kia Optima. The contact stated that while driving at 60 MPH, during a DoorDash delivery, the vehicle vibrated. The contact pulled to the side of the road and noticed smoke emitting underneath the vehicle from the right side. The contact exited the vehicle and noticed smoke emitting from underneath the hood. The state troopers were called. By the time the fire department arrived, the vehicle was engulfed in flames, and the engine had exploded. The fire department extinguished the fire. The contact was not injured. No police report was filed. The state troopers believed that the fire was caused by an electrical short. The contact stated that prior to the fire, the vehicle vibrated when idled. No warning lights were illuminated. The vehicle was towed to a towing yard. The insurance company was not notified about the fire. The contact was unaware that NHTSA Campaign Number: 21V331000 (SERVICE BRAKES, HYDRAULIC) was associated with the VIN. The manufacturer was not notified of the fire. The failure mileage was approximately 174,000.