A typical call starts the same way: a parent noticed the garage door hesitate, bounce, or not reverse when something was underneath it, and they want someone to look at it before it happens again with a kid or a dog in the way. Sometimes it's a toddler who ran under a closing door chasing a ball. Sometimes it's a dog that darts out just as the opener kicks on. The door itself is usually fine on the surface. What's actually failed is one of the safety systems built into it, and in a lot of these homes, nobody knew those systems existed until they stopped working.