Action blip of Mall Maintenance Workers

When I went to my Apple One to One class at Fashion Valley Mall, the bottom walkway was almost completely cordoned off due to these workers on the second level. I had to squeeze along a narrow corridor and duck under caution tape to arrive at my destination.
As near as I could tell, they were sanding the metal pergola beams; perhaps to remove rust?
I'll return next week and see if I can detect any changes.