On Tuesday, Massachusetts’ attorney general said that she will investigate T-breach, Mobile’s which exposed the personal information of more than 53 million individuals.

After the third-largest US telecom provider reported the incident on August 16, Attorney General Maura Healey announced the investigation.

Names, birthdays, social security numbers, driver’s license information, PIN numbers, and other personal information of an estimated 13.1 million current and 40 million previous and potential T-Mobile users were exposed in the incident.

It was one of numerous cyberattacks in recent years that impacted a variety of businesses, including banks, gas pipelines, and hospitals, among others.

T-Mobile did not reply to calls for comment right away. The hack did not disclose bank, credit card, or other payment information, according to the company.

Healey intends to look into whether the Bellevue, Washington-based firm has adequate measures in place to secure consumer data and mobile devices.

Last month, the US Federal Communications Commission launched an investigation into the matter.

According to court records, consumers and other private plaintiffs have filed at least 23 lawsuits against T-Mobile as a result of the data leak.