The second Citizen’s Fire Academy class offered a ride in Tower One and focused on fire safety information.According to McMinnville Fire Department training officer Phil Mitchell, the fire triangle refers to the three items that must be present for a fire to occur.“Oxygen, heat and fuel,” Mitchell said. “You have to have all three of those things for a fire. The main causes of fires are candles, extension cords, improperly placed heaters, smoking in bed, not emptying ashtrays, faulty wiring, and careless cooking habits.