(CHICAGO) Metra Electric trains were running again after a power outage halted the line just outside of Chicago on the South Side Tuesday morning.

Metra was notified of the outage at 8:20 a.m. after inbound and outbound trains lost power between the Museum Campus and Van Buren stations, according to Metra spokeswoman Meg Reile. Trains began moving again about 9:05 a.m.

The power outage is still under investigation, Reile said, but a broken piece of equipment in a signal station was believed to be the cause. In all, eight Metra Electric and two South Shore trains were held due to the outage.

Delays are expected to continue for several hours as trains run at a reduced speed on the line, Reile said.