The man made his way from his friend's house in Barking, Essex and ended up six miles away in Romford.
The first words to come out of a homeless man who fell into a drain and spent over three days in the sewers upon being rescued were: 'Got a fag (cigarette)?'
48-year-old David Miller was on the way to the pharmacy to collect a prescription when he fell.
He told the Romford Recorder, "All I remember is a big bang and then darkness. I thought 'I am going to die in here'."
Miller made his way from his friend's house in Barking, Essex and ended up six miles away in Romford.
He is thought to have wandered through pipelines for up to 72 hours as he desperately tried to get out.
When local business workers near Brentwood Road heard his muffled cries for help they rushed to rescue him from below the manhole cover.
Miller sustained injured to his legs and feet, and was rushed to the hospital. He even received treatment for hypothermia.
Network engineers from Thames Water are carrying out investigation into the matter.