BOSTON (AP) — The frigid conditions are taking their toll on the nation's fifth-largest transit system.

The Massachusetts Bay Transportation Authority reported "severe delays" on the Orange Line Friday, citing a broken piece of track and a disabled train among other problems.

Keolis Boston, which operates the commuter rail system for the MBTA, also reported delays on several of its lines.

Keolis spokesman Tory Mazzola said crews worked through the night to repair cracked rails and broken switches ahead of the morning commute, "but even with the best precautions train service can be impacted with the extreme conditions we're experiencing."

Commuters were advised to dress in layers to stay warm while waiting on platforms.

The T has spent heavily to winterize the transit system since it was crippled by record-breaking snowfall in 2015.