Artists collect more than 30,000 knots for papal art exhibit depicting life's daily struggles

FILE- In this May 22, 2015 file photo, artist Meg Saligman shows knots tied to a mock-up of an art installation at her studio in Philadelphia. The installation is planned to be in the shape of a latticed grotto and will greet Pope Francis and millions of others when they travel to Philadelphia this fall. Visitors will be invited to leave their own problems behind in the form of knots affixed to its walls, or help others by loosening and removing a knot already in place. (AP Photo/Matt Slocum, File) (The Associated Press)

Artists in Philadelphia have collected more than 30,000 knots representing life's daily struggles for an exhibit honoring the pope.

The knots will be housed in a grotto next to the city's Roman Catholic cathedral. Pope Francis will celebrate Mass at the basilica on Sept. 26 during his two-day visit.

The installation is inspired by one of the pontiff's favorite paintings, "Mary, Undoer of Knots." It shows Mary untangling a long ribbon — a symbol for smoothing life's difficulties.

At a recent public event, people wrote their burdens on strips of cloth and then knotted them. Challenges ranged from addictions to student loans to health problems.

Participants also were invited to untie someone else's knot — to share that person's hardship.

Organizers expect the grotto to open Sept. 3.