The investigation into a blaze that ripped through the former Bombardier factory in Mansfield remains unsolved one year on.
The fire, exactly one year ago today on July 31, 2018, saw firefighters from Nottinghamshire and Derbyshire tackling the flames from about 7pm through until the afternoon of August 1.
Shops and properties near the derelict Victoria Street building were evacuated while emergency services brought the fire under control, and some nearby buildings even suffered smoke damage from the flames.
The building, which was once occupied by manufacturer Bombardier and electronics firm Whiteley's, was subsequently demolished and remains unused.
A CCTV appeal was launched following the blaze and five youths were identified, but there was no sufficient evidence suggest they were responsible for causing the fire.
All were released pending further investigation, but no new evidence has come up in relation to the blaze and nobody has been charged with the destruction.
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Nottinghamshire Police have said that, despite a "comprehensive investigation" taking place. no further action would be taken in relation to the blaze and that the case remains "undetected".
Detective sergeant Matt Scott said: "A full and comprehensive investigation has taken place which culminated in the arrest of five juveniles.
"At the conclusion of the investigation and completion of all enquiries, it was deemed that there was not enough evidence against those arrested and no realistic prospect of conviction.
"As such, all have been notified that there is to be no further action taken.
"The exact cause of the fire remains unknown, but arson was the probable cause.
"No other suspects have been identified to date and the matter remains undetected and filed."
Police are still keen to speak to anyone with information about the blaze.
If you know anything, or think you can assist them in their enquiries, call Nottinghamshire Police on 101 quoting incident number 869 of July 31, 2018