According to the Fire Service sources, the fire broke out at the Binapota 132/33 KV power grid line around 11:10 am as a transformer exploded with a big bang.
On information, two firefighting units rushed to the spot and brought the blaze under control after an hour.
No casualties were reported.
Russel Islam, in-charge of Satkhira power grid line, said the explosion led to a complete power outage across the district.
Efforts are underway to restore electricity and supply is expected to return to normal by the evening, he said.
Nurul Islam, warehouse inspector at Satkhira Fire Service, said in preliminary investigation shows that the fire originated due to overheating or an electrical short circuit in the transformer.
The power outage has severely disrupted life in the district affecting mills, factories, businesses and daily activities, reports UNB.