Unimaginable tragedy struck in Alabama on Saturday, where two brothers, ages 3 and 1, died in a hot car that they climbed into themselves, USA Today reports. The boys' parents told authorities they thought the toddlers were playing in their bedrooms, but following a frantic search after being unable to locate them, found them unresponsive in the car. The sheriff's office tells AL.com it is investigating but believes the situation to be a "tragic accident." The children were believed to have been locked in the car for more than an hour. According to Kids and Cars, 17 children have died in hot cars this year, with 47% of those cases being kids who got into the car on their own. (On average, those types of cases account for 26% of all hot car deaths each year.)