Sen. Charles Schumer (D-NY) warns that the April 16, 2014, attack on a California power plant proves that terrorists could take down whole stretches of the U.S. power grid, according to The Associated Press.

Schumer said Sunday that power companies currently have the right to veto proposed security requirements, but he is calling for the federal energy regulator and the Department of Homeland Security to draft tougher security standards overseen by Congress that would end the industry’s veto rights.

The perpetrators of the April attack, which nearly brought down power to all of Silicon Valley, are still at large.