The mum-of-two was leaving a friend's house with her daughter Faith and eight-month-old son AJ, when the accident occurred earlier this week.
As Michelle strapped her son into his car seat, she asked Faith to stand back from the road as she was concerned about her safety.
But when she turned to look for her daughter a second later, Faith had disappeared.
"Any parent, grandparent, god parent, etc can only imagine what went through my head," Michelle writes in her OK! magazine column. "Had someone taken her? Had she stepped out onto the road?
"I shrieked: 'Faith' so loudly AJ burst into tears and Faith wailed which I recognised as a cry for help. She was at the bottom of the [man]hole!"
Michelle writes that she had spotted the manhole on her way over to the car, but as it had a cover over it she hadn't thought of it as a danger.
However, the cover wasn't properly secured and there was a small gap through which Faith fell.
The hole was too deep for Michelle to reach her daughter by herself, but two builders who were working nearby ran over to help.
One lowered himself into the hole with the other man's support and they passed Faith - who was covered in sewage and a few scratches, but otherwise unhurt - into her relieved mother's arms.
"After a bath, lots of cuddles and chocolate, she was as good as new," writes Michelle. "She was lucky she landed on her bum. It could've been a lot worse.
Let's take this as a warning to never assume a manhole is safe.
Michelle said that she'd decided to share the terrifying incident as a 'warning to others' and it seemed to have the desired effect as tweets quickly started flooding in praising Michelle for her story.
@wonderwomanshel thank you for highlighting the potential dangers of the man hole. Loving your youtube blogs, I'm already hooked!
- Yasmine Newman (@YasmineNewman) November 14, 2014
- kezzie (@mulcahy_kerry) November 14, 2014
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