A "reclusive" pensioner died when her bungalow, filled with horded possessions, burned down in a "fierce fire" on New Year's Eve, an inquest has heard.
Susan Crapp, 69, and her two dogs died at her lifelong home in Looe, Cornwall.
Miss Crapp struggled with mobility due to obesity and would have soon collapsed in the smoke due to her heart disease, the Truro inquest heard.
Investigators could not confirm the cause of the fire due to severe damage.
Miss Crapp's body was so badly damaged she could only be identified by dental records and the serial number on a metal plate in her arm.
The fire was reported at 19:50 GMT on New Year's Eve 2017 but the her body was not found until 14:43 the following day, the inquest heard.
Neighbour Robin Pengelly, who described Miss Crapp as a "recluse", said when he saw the fire it was "too fierce to allow any safe rescue attempt".
Richard Gibbons, fire investigation officer with Cornwall Fire and Rescue Service, said every room was full of belongings, which probably made the fire develop rapidly.
He concluded a number of factors could have caused the blaze, including the close proximity of gas heaters to clothing and electrical equipment, a spark from an open fire or even a rogue firework.
Forensic pathologist Amanda Jeffery said Miss Crapp died from smoke inhalation, adding that her severe heart disease "would have played a significant role".
The inquest also heard there was an 11 minute delay in fire crews reaching the scene due technical system faults.
A Cornwall Fire and Rescue Service spokesperson said this would not have made a difference, however they added improvements had been made.
Cornwall coroner Emma Carlyon recorded a conclusion of accidental death with no evidence of "third party involvement".