A man in his 50s died after an "explosion" destroyed a house with a passerby injured as he tried to help.
The man was found dead after officers were called to the property following reports of an explosion. Lincolnshire Police said the house suffered "100 per cent damage".
Emergency services tried to save the man, with help from members of the public, but he was later pronounced dead at the scene.
The incident happened in the early hours of Sunday morning at a property on Farrow Road, Spalding.
Lincolnshire Police said the man's next of kin have been informed.
The force said in a statement: "The cause of the fire is under investigation, and we are keeping an open mind as experts from Lincolnshire Fire and Rescue Service investigate today.
"We would encourage people not to speculate while we investigate the cause.
"Another man who is thought to have been passing by the property and offered his help suffered burn injuries and is currently receiving treatment. Officers will remain in the area for the next few days carrying out enquiries."
Police are now asking anyone who saw or heard anything, or who captured the incident on doorbell camera or dashcam, to get in touch.
People can call 101 or email control@lincs.police.uk, quoting incident number 43 of August 7 in both cases. People can also contact CrimeStoppers anonymously on 0800 555 111.
