Bay Area Rapid Transit officials closed three East Bay stations on Sunday afternoon because of a series of electrical fires that occurred Saturday at the South Hayward train yard. Officials also told passengers who took the Fremont lines to expect delays of about 15 minutes this week.

According to the San Francisco Chronicle, BART spokesman Jim Allison said that the situation was caused by a series of electrical fires which damaged cables leading from a tower that helps control the trains. Until repairs are finished, the trains will have to be operated manually on tracks south of the Bay Fair Station.

“There was physical damage to a very critical component of the train control system. The tower at the Hayward yard, where we move trains around and get them ready to go, is out of commission,” Allison said.

The trains between the Hayward and Fremont stations were stopped for nearly 16 hours on Saturday. Trains were running at all stations Sunday morning, but BART officials closed the South Hayward, Union City and Fremont stations again at 2 p.m, as the San Francisco Chronicle reported.

Passengers who planned to travel on the Richmond-Fremont line between Hayward and Fremont will have to transfer to Daly City-Fremont trains at the Bay Fair Station.

The problems caused by the fire will take weeks to be solved and the damages cost BART millions of dollars.

Reports show that the fires might have been caused by employee errors and may be related to upgrades performed by BART technicians early Saturday. The fires are still under investigation.