Indiana’s state health commissioner says she’s concerned about the rising rate of coronavirus cases, and warns the numbers could go higher again after Labor Day.

Kristina Box says a lot of Indiana’s new cases date back to people letting their guard down to celebrate the Fourth of July, and says she’s concerned it’ll happen again with the next holiday weekend. She says contact tracers have frequently linked cases to weddings, funerals, and graduation parties. In one cluster of school cases, Box says, a high school football team and cheerleading squad had thrown a party to celebrate the reopening of school.

Indiana’s seven-day average rate of positive cases bottomed out at 4.9% on June 21. Beginning five days later, the daily positivity rate has been at least 6% every day, driving the weekly average as high as 8% on July 10. After leveling off, that average has held steady or risen every day since July 30, and currently stands at 7.8%.

The upturn began two weeks after bars and casinos were allowed to reopen, but Box and Governor Holcomb say most businesses are taking proper precautions. Box says local health inspectors have closed a few who have ignored mask and social distancing requirements, but Holcomb says businesses and schools have generally been well protected against the virus — he says it’s been the private gatherings that have sparked clusters of cases.

Box says the biggest surge in cases has been among teenagers and people in their 20s.

Holcomb had initially planned to lift the last of Indiana’s restrictions on large gatherings and capacity limits at bars, restaurants and clubs on the Fourth of July. The upturn in cases prompted Holcomb to leave those restrictions in place, with the current expiration date now set for August 27.