New Jersey went from being one of the country’s worst Covid-19 hot spots to a model of how to flatten the curve.

Now, two months into the first summer of the pandemic, it’s backsliding. New cases are way up and the state’s rate of spread nearly doubled in the past four weeks as keggers, house parties and packed-to-the-gills vacation rentals became infection hubs.

If fresh scars of the pandemic’s darkest days and strict orders from the governor weren’t enough to keep tourists and residents from pretending 2020 was simply another raucous summer down the Jersey Shore, the future will be grim for other states that have been less aggressive.

New Jersey, where 16,000 residents are believed to have died from Covid-19 since March, is serving as a test case of whether any state can really reopen safely. The experience could be a harbinger for states like New York and Connecticut that also clamped down early.