A couple and their infant were accidentally locked in a Kmart KDollar store in Bloomfield Township, Mich., apparently going unnoticed by store staff at closing time.

Sgt. Timothy Abbo of the Bloomfield Township Police Department said police responded to a burglar alarm on March 25 at a Sears Outlet and Kmart KDollar store, ABC affiliate WXYZ reported.

"We're investigating how this unfortunate incident happened," said a spokesman for Sears Holdings, which owns Kmart.

When they arrived, "officers discovered a male, female and infant locked inside," according to the police statement.

The Sears Outlet store, which is owned by a company separate from Sears Holdings Corp., did not respond to a request for comment.

With the help of the officers, the couple unlocked the doors and exited the building, police say.

"We don't believe there was any wrongdoing on the couples' part," Sgt. Abbo told ABC News. He said the police do not release the names of individuals unless they are arraigned or charged, but Abbo said the couple is in their 30s and from Pontiac, Mich.

"The couple said they were shopping and suddenly realized that there were no longer any employees in the store. Apparently Kmart workers had closed and left the building not realizing they still had customers inside. A store representative arrived to re-secure the building," the police statement said.