The foundation has urged the return of stolen items, saying they mean so much to bereaved families.
The glass display case at Manchesterplatz, which has been fixed, contains memorabilia and tributes commemorating the Munich air disaster
A glass sculpture and medals have been stolen from a memorial to the 23 people killed in the Munich air disaster, including eight Manchester United players.
The items were taken from a display case at Manchesterplatz in Munich, where the plane crashed on take-off on 6 February 1958 after refuelling on its return from a European Cup match in Belgrade.
Munich Police told German media the glass was smashed with a stone and said the incident was believed to have happened between 08:00 and 13:00 local time on Monday, 26 October.
The Manchester Munich Memorial Foundation (MMMF) said it was "deeply saddened", while its chair, Ifty Ahmed, said the theft had caused emotional harm to families.
Source: BBC Sport