Around 4 p.m. Sunday, a power outage put 5,400 AEP customers in the dark across portions of Elkhart and St. Joseph Counties in Indiana and Cass County Michigan.

Kim Sabrosky, a spokeswoman with AEP tells NewsCenter 16, a handful of line crews were spread across the area looking to pinpoint the cause.

They later traced the Elkhart County outages to a transformer issue and managed to restore power by late Sunday night.

As of 10:30 p.m., crews had not found the cause for the outages in St. Joseph County and did not have an estimate for when power would be restored.

At this hour, 450 customers are still without power in St. Joseph County.

Stay with NewsCenter 16 for updates.