A cyberattack on a Florida water treatment plant underscores the need for strong security protections at the municipal level, attorneys and industry professionals say.

A hacker gained access to an Oldsmar, Fla. city computer on Feb. 5 and changed the level of sodium hydroxide, also known as lye, local authorities said. It isn’t yet known whether the breach originated from the U.S. or from outside the country. The Federal Bureau of Investigation is working with local authorities.