A woman and her dog plunged 12ft down a manhole after thugs removed the cover.
Chris Long, 59, fell down the hole in the dark - and her nine-year-old golden retriever Sam landed on top of her.
The walker said she feared the worst when she fell but was able to clamber to safety.
Escape: Chris Long, 59, plunged down a manhole in the dark after thieves apparently removed the cover
It is believed that thieves removed the cover thinking it contained metal which could be sold for scrap - but then abandoned it when they realised it was concrete.
Mrs Long flagged down a passing driver who helped her rescue her golden retriever. She had a second dog with her which didn't fall.
BT said they have launched an investigation but added that they thought the cover had been 'disturbed deliberately' in Sedgeberrow, near Evesham, Worcestershire.
Mrs Long was taken to hospital with a large bruise on her head and a twisted ankle.
She said: 'I really felt I was going to die, I was so lucky not to have been badly injured,' she said.
'The hole was so deep that even a twisted ankle would have prevented me getting out. As it is the experience was very traumatising.
'Ironically, I walked that way for safety reasons as it is not my normal dog walking route. I did not see the uncovered hole in the dark and it felt like I was plummeting down a mine shaft.
'I really thought 'I am dead.'
A spokesman for BT said they were investigating and said public safety is their 'utmost priority'.
A passing car stopped and a couple got out to help rescue the dog. They tried to replace the manhole cover which had been lying at the side of the hole.
Mrs Long added: 'Someone was responsible for leaving the manhole cover off - I think it must have been there for a little while and it was concrete not iron like a lot that have been stolen.'
Jon Fraser, from Worcestershire County Council, said: 'Whilst the reasons why the BT manhole was left open are unknown, we have suffered many instances of vandalism and theft of manhole covers in recent times.
'We do of course inspect all of Worcestershire's roads regularly and would encourage anyone that notices any defects, particularly dangerous ones, to contact us immediately so that we can take appropriate action.'