Today, the exact location of Mrs Blunden's tomb is unknown, but the story certainly seems to be true. In fact, there is evidence to suggest that many years ago in England, up to 1 in 25 corpses showed evidence that they had been mistakenly buried alive. This discovery is believed to have led to the attachment of bells to corpses, by means of tying a length of string around the departed's wrist or finger, which would then be attached to a bell above the ground. Then if the corpse should wake, someone above ground could be alerted by the unfortunate person's movements.
This gave rise to the sayings "Saved by the bell" and of course "Dead ringers"