Severe damage has been caused to 40% of a derelict building in Sutton on Sea after a fire yesterday evening.
The fire on South Road broke out at 6.50pm on July 4, with crews from Mablethorpe, Alford and Skegness attended.
Firefighters also requested the aerial ladder platform based in Boston.
Crews used four main jets, four hose reels, two breathing apparatus and thermal imaging cameras to extinguish the fire.
The cause is still under investigation.
However, police would like to trace two teenage boys who were seen in the area at the time.
The first boy is described as wearing a grey hooded top and aged about 16.
Police have said that the second boy is aged 11 and wearing a 2/3 blue waterproof coat and baseball cap.
Anyone who recognises these boys from the description should call Lincolnshire Police on 101.