God yes!!!
My ds (was three at the time, and we thought 'quie clued up') had some venetian blinds in his room.
We used to pull them up in a morning, so the cord ended up really long.
Also under my sons window, was one of those large ride on thomas the tank engines.
One day I was in my room, and I heard him crying.
He had CLIMBED onto his windowsill, WRAPPED the blind cord around his NECK , and JUMPED off the windowsill!!!!!
LUCKILY the train was there, and he had managed to balance on it on his tip toes, therefore, not strangling himself to death!
He was ok, but he was left with a bruise and scabs around his neck for about a week.