PHILADELPHIA (CBS) — Riders will have their commute affected after cracks were found in SEPTA’s Market-Frankford Line cars.

Beginning Monday morning, between 30-40 more will be removed.

SEPTA officials say about one-third of its fleet will be taken out of service Monday.

Officials will hold a press conference updating the situation at 1:00 p.m.

SEPTA’s Carla Showell-Lee said they are working to make this inconvenience as smooth as possible for riders.

“People should know that the Market-Frankford Line trains will continue to operate between 69th Street Transportation Center and the Frankford Transportation Center,” she said.

“We’re gonna have shuttle buses, about 60 out there between the peak hours of 6 a.m. and 10 a.m. and then 3 p.m. until 7 p.m. at select stations.”

Trains will operate with longer headways, and supplemental bus service will be provided.

Market-Frankford Line trains will be running tomorrow between 69th Street Transportation Center and the Frankford Transportation Center.

SEPTA is advising riders give themselves plenty of extra time.

All service information can be found at SEPTA.org.