EMBED >More News Videos Chicago Mayor Lori Lightfoot will participate in a roundtable drill that will lay out some worst case scenarios to prepare for the upcoming Lollapalooza festival.

CHICAGO (WLS) -- The shooting at a garlic festival in Gilroy, California , on Sunday raised security concerns in Chicago with Lollapalooza set to begin this week.Lollapalooza starts Thursday and security preparations for the event are underway. The four-day world-renowned music festival is expected to draw 400,000 people to Grant Park."It's a worldwide event and it's right here in the Loop and we're really proud to be a part of it," said Michael Edwards, president and CEO of the Chicago Loop Alliance.According to the Chicago Loop Alliance, in addition to the large crowds of locals and visitors in Grant Park, during the week there are 2 million who come through the downtown area."It's the highest peak of pedestrian counts on State Street throughout the year," Edwards said.With crowds of that size, city officials said there will be a robust safety and security plan in place. Lollapalooza works with local state and federal agencies to ensure crowd safety. Both uniformed and undercover officers are mixed in with the crowds."You're going to see Chicago Police Department in uniform. You're going to see Chicago police in some of the hotels, in businesses along Michigan Avenue. We have undercover units that are assigned to this event, as you would expect," said Rich Guidice, executive director of the Office of Emergency Management and Communication.Mayor Lori Lightfoot also addressed Lollapalooza security plans in light of the tragedy in Gilroy."We are vigorously, aggressively reaching out, planning and drawing upon resources from our federal partners to make sure that there's no incident here in Chicago," she said.Bay Area authorities said the 19-year-old shooter cut through a fence to avoid the tight security at the garlic festival. OEMC said it would take more than that to sneak into Lollapalooza."This is what we call the 'needle fencing,'" Guidice said. "This is a pretty significant piece of equipment that is utilized for this event. You would need high powered tools to try to breach that, the fence that is put around the perimeter of the event."Barriers are also set up to block the way of cars.With such large crowds police cut down on what you can bring into the festival. Backpacks with multiple pockets are not allowed and any small bag brought in will be searched at the door."Lollapalooza is a world-class event that draws music fans from around the world to enjoy performances against the backdrop of our world-class skyline," said Guidice. "As always, public safety is our top priority for the event, and the City works year-round with the organizers to plan and prepare for the safety and security of attendees, performers and staff at the festival while ensuring a fun and memorable experience."Liquids will not be allowed into the festival, but festival-goers may drink while in line as long as containers are empty prior to entering. Free water will be provided at hydration stations.For more information on prohibited items, visit www.lollapalooza.com/information