
Police said the fire started at around 4am at the Udomsup shop on Pathum-Tiwanon Road in tambon Klong, Mueang district.
Firefighters arrived on the scene in 10 fire engines and had the blaze under control by about 7.30am.
While fire fighters were trying to control the blaze, Prateep Udomratanawit, 40, and his wife jumped down from behind their shop. They were taken to Pathum Thani Hospital.
A neighbour, Krit Jaichalad, 36, told police that he heard a strange sound and came out of his house to see the fire raging. He shouted to the shop owner but no one answered. Later, he saw the couple jump from the building.
Police said the fire spread very fast because the shop sold engine oil and plastic parts for vehicles. There were explosions while fire fighters were trying to put the fire out.
The fire caused about Bt10 million in damages, police said.
The fire fighting effort caused heavy traffic congestion on the road.