Under a driving rain, crews continued to set up for this weekend's three-day Boston Calling music festival.
"We start with safety and security, and then we build everything from there," co-founder Brian Appel said Thursday.
After hosting the event at City Hall Plaza for a number of years, this is the first year the concert will be at the Harvard Athletic Complex.
The new location meant a new security plan, one that was elevated after Monday night's attack at a concert in Manchester, England.
"There will be much more of a visible presence on site throughout the weekend," Appel said.
Festival organizers say they expect 40,000 or more fans a day at the three-day event. Those who attend will pass through metal detectors. People will also be limited in what they can bring into the festival, and it must fit into a 12-by-12-foot bag.
Organizers credited Boston Police, Massachusetts State Police and Cambridge Police for being proactive in addressing enhanced security measures.
"In generalities, they have added significant deployment for us, which we are very appreciative of because they are working with us to make sure this event is going to run very smoothly," Appel said. "Everybody just buttons down a little bit more and takes some enhanced security measures and the show goes on."