Belmont Savings Bank has agreed to pay $7,500 in a settlement following a data breach in which an unencrypted backup computer tape containing the names, Social Security numbers and account numbers of more than 13,000 Massachusetts residents was lost after a Belmont Savings Bank employee failed to follow the bank’s policies and procedures.

"Consumers expect businesses to not only develop policies and procedures to safeguard their sensitive personal information, but to follow these procedures as well," Attorney General Martha Coakley said in a statement. "Our office will continue to take action against companies that fail to follow protocol to protect the information entrusted to them by consumers."

The data breach happened in May, when an employee left a backup computer tape on a desk rather than storing it in a vault for the night, according to a statement. Surveillance footage showed the tape was thrown away by the evening cleaning crew.

The tape was most likely incinerated by Belmont Savings Bank’s waste disposal company. Belmont Savings Bank indicated it has no evidence that consumers’ personal information had been acquired or used by an unauthorized person or used for an unauthorized purpose.

Under the terms of the settlement, Belmont Savings Bank must ensure the proper transfer and inventory of backup computer tapes containing personal information; store backup computer tapes containing personal information in a secure location; and effectively train the members of its workforce on the policies and procedures with respect to maintaining the security of personal information.