The cause of the fire that destroyed the old Roberts Shoes building, which was a hub for artists and musicians, will be left as undetermined, Minneapolis investigators said Wednesday.

The fire swept through the old brick building at the corner of Lake Street and Chicago Avenue on Saturday. No one was injured.

During the fire, the roof collapsed. The building was left structurally unsound and was at risk of collapsing, preventing crews from getting inside to investigate the cause of the fire. The building was demolished on Wednesday.

Fire officials said it appeared the fire started in the building’s boiler room.

The building was the home of Robert Pirsig when he wrote “Zen and the Art of Motorcycle Maintenance” in the 1970s and housed arts organizations such as In the Heart of the Beast theater.

In recent years it became a low-rent space for artists or musicians looking for a studio — available 24 hours a day with a community of artists who supported one another, often sharing units and pooling the money for rent.

Filmmaker and artist Alex Uhrich created an online fundraising campaign — Robert’s Shoes Displacement Fund — to help the artists who lost their studios and in some cases, living spaces. As of Wednesday, more than $14,000 of the $50,000 goal had been reached.