Miro Damaged at Tate Modern.

A monumental piece by modern artist Joan Miro was damaged and repaired while on loan to the Tate Modern for their Miro retrospective, an event that evaded the media and went unreported till recently. The painting, one of a large triptych, was said to have been damaged accidentally by a visitor to the retrospective and while it has been repaired, the damage is apparently still visible and depreciated the value of the piece significantly. Take a look.
http://theartnewspaper.com/articles/Mir%C3%B3+on+loan+damaged+at+Tate+Modern/28341