Iranian hackers reportedly breached Bowman Avenue Dam near Rye Brook, New York in 2013 and were able to take control of the flood gates, according to a former official. The cyberattack was reported by The Wall Street Journal on Monday.
According to the former official, the hack was a test by the hackers to see what they could access.
The hackers were reportedly able to take control of the flood gates. The dam is used to prevent flooding downstream.
News of the hack exacerbates a fear of cyber experts: that overseas hackers can get into pieces of critical infrastructure connected to the Internet. The dam is managed by a piece of software described as "industry standard" and "very common."
Security experts have repeatedly expressed concerns about an attack on the U.S. electrical grid or industrial control systems. Most of the critical infrastructure in the U.S. is privately owned, so the government is limited in its ability to protect them against attack.
The Department of Homeland Security did not comment, but said its cybersecurity center serves as a hub for monitoring and mitigating attacks.
"The Department of Homeland Security continues to coordinate national efforts to strengthen the security and resilience of critical infrastructure, working with our federal and industry partners across the country to raise awareness about evolving threats and promote measures to reduce risks to systems we all rely on," the department said.
New York lawmakers pointed to the news as an example of the need for greater attention on cybersecurity.