The Brief Cleanup was underway Monday after a rain-soaked Lollapalooza weekend in Grant Park. Lost items can be claimed at the festival's lost and found at the Hilton Chicago from 10 a.m. to 5 p.m. Monday. A muddy Grant Park is being cleaned up after another packed Lollapalooza weekend, and festivalgoers who left belongings behind have a chance to get them back. Lollapalooza lost and foundWhat we know:Cleanup crews got to work Monday after four days of music, large crowds and heavy rain left parts of Grant Park covered in mud and litter. The backstory:It's still too early to know how much this year's Lollapalooza cleanup and repairs will cost.