The toddler was filmed by a neighbour who alerted police after spotting him playing on the ledge, seemingly oblivious to the danger.
Debbie Green held her breath as she watched the boy wander along the edge, swinging his legs out over the sheer drop.
She said: "My heart was in my mouth. I was sure he was going to fall to his death.
"I grabbed the phone to call police and my husband got his camera with a zoom to see close up that it actually was a little kid and not some doll.
"The police arrived after about six or seven minutes but it felt like hours. I've never felt so scared, it was horrendous."
Debbie's husband John, 42, said: "I feared I was about to film this child's death. I was amazed he was able to keep his balance."
Police who went to the flat on the eighth storey of a tower block say they found the boy's mum and a man asleep inside.
Officers said she claimed her lad had been safe because there was flimsy pigeon netting over the open balcony.
But Debbie, 40, said: "It's ridiculous. No way would it have held him." The mum yesterday said she was grateful to Debbie.
But she insisted she had been doing the cleaning when her son slipped on to the balcony in Wyken, Coventry — not sleeping.
She said her friend was supposed to be keeping an eye on the lad but fell asleep watching TV.
She added: "The doors in the flat don't shut properly and he must have got on to the balcony.
"When the police told me what my son had been doing I was shocked. I'm still shaking now, I cannot believe it.
"I won't let him out of my sight now. I'd like to thank the neighbours over the way who saw him."
Fucking crazy world man
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