I've name changed for this.
I'm not sure what I want from posting really, I just need to get this off my chest as I'm absolutely gutted and I'm so upset with myself.
I live in a ground floor flat which is all on one level. It's opposite an old police station which is mainly used as a PSCO hub now.
This afternoon my DS who is 2.5 and has autism was laying in my bed watching videos on his tablet, he was perfectly settled and engrossed in his tablet.
My bedroom window has two openings, a small one at the top left hand corner and a large one which opens outwards that runs horizontally down the whole right hand side.
I wasn't far from the bedroom but the Hoover masked the sound of him rustling the blinds and climbing out. I was out of the room for a matter of minutes and when I went back in he had gone.
The bedroom window opens out into a large driveway / alley which leads to further flats at the back, then at the front of the alley is there is junction leading to three different streets so I didn't know which way he had gone.
I'm running back and forth screaming his name when cars start beeping at the end of the road, I looked and caught a glimpse of his yellow shorts at the end of the block.
The traffic had stopped and people were getting out of their cars.
A kind man managed to catch him and hold him until I could catch up and if he hadn't he would have almost certainly been run over as he would have ran into the road. He has no concept of danger and no understanding 
This is a main road where I live and there has been 4 or 5 accidents down here in the period since I moved in so it couldn't have happened at a worse place.
I got him home and he's laughing like he's had a great time, a few minutes later the police arrive to see if I'm ok and what's happened as they could hear me screaming and didn't know what was happening.
I feel like the worst mother I've ever known. Who doesn't get child safety locks for windows for fuck sake?
My only defence, which isn't even a valid defence, is that he hadn't shown any interest in escaping before, but I should have pre empted it. It's basic parenting isn't it.
My nerves are shot to pieces.
I remember seeing something similar on TV once, a toddler escaped and ran away before being picked up by the police, yet I had the gall to judge the parents.
Has anything like this happened to anybody else?
I'm prepared to be flamed. I deserve nothing less.