As Nelson grew up, it was time to redecorate again -- but painting over the cards wasn't an option, and, as Brodt later discovered herself, they were glued on too tightly to pull off.
Knudsen was also well known for his love of sports.
Brodt said her son Luke tried to remove a few, but the pictures just tore away from their cardboard backing.
The agency is urging athletes and other participants to leave their personal phones and other devices behind and use burner phones instead to protect themselves against potential cyber threats and data thefts.
For now, the wall's fate is undecided.
The girls featured in the clip are part of a group who go by the name the eighty83three squad.