The picture shows that part of the hospital was swallowed by black smoke.
The head of the hospital confirmed that a lightning bolt struck the building on Wednesday and lit the roof.
As firefighters put out the fire, some patients have been evacuated from one of the wards.
Just after 2:20 in the afternoon, seven fire trucks were called.
This hospital in Flixton, Greater Manchester is said to be the birthplace of the NHS.
A spokesperson for the Greater Manchester Fire and Rescue Service said: “The staff rushed to the scene quickly, and the aerial ladder platform of the Manchester Central Fire Station also joined in.
“Firefighters wearing respirators are currently using two hose reels and a jet to extinguish the fire involving the two-story roof. The staff are still present at this time.”
It is believed that the Seymour Building was struck by lightning in a thunderstorm.
A spokesperson for the Manchester University NHS Foundation, which manages the hospital, said; “We can confirm that an area of Trafford General Hospital was struck by lightning and caused a fire in the roof area.
“A few patients and staff have been safely evacuated from a ward, and the Greater Manchester Fire and Rescue Service is currently on duty. “This is an ongoing incident. “
