U.S. senators participated in a multi-agency exercise Wednesday simulating how the government would respond in the event of a cyber attack crippling New York City’s electric supply during a summer heat wave, according to an article from Information Week.

Top cybersecurity officials from various departments and agencies, including the White House, the Department of Homeland Security (DHS), FBI and National Security Agency, participated in the event. The exact details of the exercise are being kept confidential, the article said.

Several bills about cybersecurity are currently in Congress, although none have yet been passed. The purpose of the exercise was to stress the need for legislation to more effectively prevent and respond to these attacks, especially risk-based performance standards for critical infrastructure systems so they at least meet a baseline level of security, said DHS press secretary Matt Chandler in the article.

National Security Council spokeswoman Caitlyn Hayden urged Congress to provide the legislation to support federal cybersecurity efforts that are already underway, according to Information Week.

 “Only Congress can modernize our underlying laws and give us the full range of tools our cybersecurity professionals need to more effectively deal with this growing and increasingly sophisticated threat,” Hayden said.