Wells Fargo & Company ATMs crashed on Monday afternoon, inconveniencing thousands of customers.

A majority of the bank's 12,000 ATMs nationwide stopped working and started displaying “Out of Service” messages Monday afternoon, according to the Star Tribune.

The outage reportedly lasted for several hours and was still not fixed by the time local branches closed. As of 8:45 p.m. Monday, Wells Fargo officials still didn't know what had caused the crash-but it had been fixed at all locations. A company representative told Twin Cities Business on Tuesday afternoon that the failure was “due to a systems issue” and that further information about the crash “is proprietary.”

During the outage, customers were able to access their money at non-Wells Fargo ATMs using their check cards, but most had to pay several dollars in extra fees to do so. Wells Fargo told Twin Cities Business Tuesday afternoon that it would reimburse customers for such fees incurred from out-of-network ATMs during the outage.

Experts said that the ATM failure was unusual in its scope and its duration. Such outages usually only last for an hour or two and are confined to particular regions of the country.

Wells Fargo, which is based in San Francisco, employs about 20,000 people within Minnesota, making it Minnesota's ninth-largest employer.

To read the full Star Tribune story, click here.