ST. LOUIS—Missouri American Water and Illinois American Water customers are being notified of a cyberattack involving the utility company. 

The company took down its customer service portal and is pausing billing while it works to bring the system back online safely. There will also be no late charges or services sut off while the portal is done. The call center also has liminted functionality.

New Jersey-based American Water — which provides services to more than 14 million people in 14 states and on 18 military installations — said it became aware of the unauthorized activity on Thursday and immediately took protective steps.

The company does not believe its facilities or operations were impacted by the attack and said staffers were working “around the clock” to investigate the nature and scope of the attack.

The company said it has notified law enforcement and is cooperating with them. 

It has posted an IT Security FAQ section on its site that will help answer some customer questions.

According to its website, American Water manages more than 500 water and wastewater systems in about 1,700 communities in California, Georgia, Hawaii, Illinois, Indiana, Iowa, Kentucky, Maryland, Missouri, New Jersey, Pennsylvania, Tennessee, Virginia and West Virginia.