Smokin

Yesterday I was babysitting the kids across the street right when they got home from school. We were hanging out. Made some popcorn. Played outside. Came back inside. Watched tv in the basement. And then the fire alarm went off. No one was smoking, as the title implies. Supposedly there was an actual fire. So I'm trying to get the kids out of the house, and find the fire at the same time. Unfortuneatly they were following me. I told them to go outside, but of course they wouldn't without me. But it was okay, because I figured out what was causing the fire alarm to go off pretty fast. The microwave was on, and nothing was in it. There wasn't a fire, it was just smoking. So I turned off the microwave, and soon after that the fire alarm stopped. It was weird though. If the microwave was still on from the popcorn, it should've created a fire long before that. The first thing we did was make popcorn so....why was the microwave randomly on? Answers are accepted. :D