Drop-in centre volunteers have spoken of their shock as strong winds tore a section of roof from Gorleston Baptist Church as they set up for lunch.
The church operates as a food bank on Thursday and was an hour away from handing out food to those who needed it, with up to 70 people expected to attend.
Around a dozen people from The Well Drop-in Centre were preparing to serve lunch, when, at around 11.15am, the roof of the church's back hall caved in under strong winds.
One man was injured after being hit on the head by a piece of falling masonry. He was taken to nearby doctor's surgery, but is now understood to be home.
Liz Townson, manager of The Well, said: 'It was such a shock. It's had a huge impact, as we have had to cancel the drop in and food bank services until we are told the hall is safe to go into.
'However, we are grateful that only one person was injured, as had it happened an hour later it could have been much, much worse.'
A man, who gave his name only as Steve, said he was in the room when the roof came down.
MORE: Thousands of homes without power in Norfolk and Forest Heath area as Storm Doris hits region'I was sitting in the room and it just missed me. Everyone in that building in that church was blessed.
'The noise was horrendous. It was like nothing I have ever heard. The wind just picked it up and it came crashing down.'
Winds of up to 90mph have been forecast as Storm Doris takes hold.
The Met Office has issued a weather warning for wind.
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