WASHINGTON (Nexstar) — Lawmakers are concerned cyber threats put the nation’s physical infrastructure at risk and they realize the US is not prepared for the attacks that are growing in number and severity.

As a witness, Maine Sen. Angus King told a Senate committee he’s most concerned about threats to the nation’s water system.

“This is an extremely dangerous situation, I believe that the next Pearl Harbor or the next 9/11 will be cyber,” King said.

Recent attacks on water systems have happened in states like Florida, Kansas and California, where Sen. Alex Padilla said a hacker accessed a water treatment plant “and deleted several programs that are designed and put in place to treat drinking water. Thankfully the hack did not result in a harm to the public.”

Lawmakers and experts say only luck has prevented catastrophic consequences because the nation is just not prepared.

Another top concern is vehicles and public transportation systems becoming smarter and more interconnected — and more vulnerable to cyber attacks.

Several pieces of legislation are in the works to increase funding and regulations.

“Increased data and access to that data can result in safey and privacy threats,” said Republican Sen. Shelley Moore Capito of West Virginia.

Delaware’s Tom Carper said, “Cybersecurity is a constantly evolving challenge, much like climate change. There’s no silver bullet.”

Leaders from public utilities and private industry say the federal government needs to act faster so the US can keep up with evolving threats.