Beaches at America’s newest national park were shut down earlier this month, after an Indiana steel factory leaked cyanide into a tributary of Lake Michigan, killing 3,000 fish.

The National Park Service closed the Portage Lakefront and Riverwalk beach area, at the Indiana Dunes National Park last Friday, according to a release from the agency. Those areas remain closed. The park was designated the 61st, and newest, national park in February after a century of seeking the title.

John Cannon, mayor of Portage, the city where the chemical spill occurred, has criticized the state’s environmental agency for waiting several days to report the incident.

“The biggest concern I had was that the city was not aware of any kind of difficulty in our waterway until Thursday when thousands of dead fish show up in our marina,” Cannon tells TIME on Tuesday. He continued: “We can handle the truth. Let us know what is going on and we can advise our residents in a proper manner without panicking.”

City officials criticized the Indiana Department of Environmental Management (IDEM) in a Facebook post last Friday saying that while the agency knew about concerns as early as Aug. 12, the city was not notified until Aug. 15. Cannon says he only learned about the cyanide leak after being tipped off by locals at the marina. The post also mentioned the city would be “taking aggressive action with the Environmental Protection Agency to ensure the breakdown of communication, like this, does not happen again.”

The IDEM responded to reports of dead fish last Thursday, according to a press release from the agency forwarded to TIME. The department learned later that day that ArcelorMittal, a multinational steel company, which owns the plant in Burns Harbor that leaked toxins, had exceeded “the daily maximum limit for total cyanide and ammonia-nitrogen.” It requested ArcelorMittal to initiate a spill response and increased monitoring of any discharge to the Little Calumet River.

ArcelorMittal has since taken responsibility for the incident, saying in a public statement they would be conducting an internal investigation and that, “We are deeply saddened to hear of the 3,000 fish estimated by [Indiana Department of Natural Resources] that were killed as a result of the incident and are working collaboratively with governmental agencies and other stakeholders to address the impacts that occurred.” It said that it “promptly reported” this to the IDEM and that the cause of the leak has “been repaired.”

The IDEM on Monday said that based on sampling conducted by the steel company, “no in stream sample has exceeded the maximum contaminant level for the federal Safe Drinking Water Act.” The state permits that these companies operate under typically require them to monitor what substances they are discharging and report those results says Robert Weinstock, a law professor at the University of Chicago’s Abrams Environmental Law Clinic.

Indiana American Water, which delivers water and wastewater services to about 1.3 million people in the state, confirmed that they did not detect any cyanide in their water but are monitoring for presence of the substance.

Mayor Cannon clarified on Tuesday that there appear to be no harmful effects on the quality of drinking water in the region. The mayor also explained that anyone who eats any fish that may have been contaminated would not be in danger.

Meanwhile, the Portage Port Authority, a local marina development, and various individuals are teaming up to sue ArcelorMittal, The Times of Northwest Indiana reports. They argue the company put people at risk and disrupted business and recreation.

This is not the first time a steel company operating in Portage would have to face litigation.

Last year, the University of Chicago’s Abrams Environmental Law Clinic sued U.S. Steel, alleging that the company discharged about 300 pounds of Hexavalent Chromium, a carcinogenic chemical, into a canal. The City of Chicago also filed a separate lawsuit alleging the same violations and the two lawsuits were eventually consolidated.

While the entities involved may be different, the core issues of industrial compliance and shortcomings in state agency oversight are the same, according to Weinstock. He says there is a need for a shift at the state and federal level towards informing the public, instead of being overly cautious.

Weinstock says the IDEM “has a lot of discretion” and perhaps “don’t want to incite panic.” But, he adds: “When you view industry as your client instead of an entity you’re supposed to be regulating, that could lead you to tip the balance towards corporate interests when thinking about whether or not to notify the public.”

Write to Sanya Mansoor at sanya.mansoor@time.com.