I started letting my oldest stay alone for 15 minutes at age 8. By age 10, I was leaving him for 30 minutes with the care of his brother and sister, then 3 & 1. I worked nights and DH worked days. There was a 30 min window between when I left and he got home. DS was very mature for his age and took great care of his siblings. I always left the baby dry & fed, and a movie on and snacks to eat while waiting for dad to come home. It worked well for many months.
And then one afternoon on my way to work, bad weather moved in. Real bad weather. A tornado was headed straight for our neighborhood.

Cell towers were down and I couldn't reach the kids or DH. I was stuck in bumper-to-bumper Atlanta traffic and couldn't move. I was crying hysterically. I shouldn't have worried so much. DS-then 10 had moved both kids to the safe room in the basement, turned on the radio and was reading them stories to keep them calm. He even grabbed a bottle on the way down the stairs. Thankfully, the tornado skipped over our neighborhood and didn't cause any damage to the house. My DH arrived shortly after the tornado passed and found the kids still in the basement, safe and sound.
In retrospect, I don't think this was a completely awful thing since everything worked out well. Still, it upset me terribly at the time and I changed my work hours so that I no longer had to leave home before DH came in.
ETA: I walked myself to school from the time I entered 1st grade. This wasn't out in the country,either. It was in a busy city.

And I had to walk through a graveyard. I guess my mom was just overwhelmed with 4 kids(I was the oldest) and she had no car. there was no bus service. So it was walk to school and hope you got there. But I would never let one of my kids do that, if I had to put all the little ones in the same stroller and walk the other one to school!