A huge Carlisle United banner paid for by fans was damaged at the Blues' home defeat to Leyton Orient.
The flag which has sat near the front of the Warwick Road End since April was torn during Saturday's 1-0 defeat.
The section of the banner which reads 'Simmo's Blue Army' was damaged.
It is not yet clear how the damage occurred.
But it is a blow after a hugely positive supporters' initiative which paid for the banner amid other displays at Brunton Park.
More than £1,600 was raised in a crowdfunding scheme as part of attempts to revitalise the Warwick Road End.
The two-part banner - the other section features the motto 'Be Just And Fear Not', which remains undamaged - was unveiled in February after 91 donations raised £1,605, with money also being spent on other flags for the stadium.
The damage took place on a day a loud bang was heard from the Warwick Road End during the first half of the Orient game.
Some fans have said a firework was let off in the home terrace. The News & Star has approached the Blues for comment.
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