There have been extensive CTA Blue Line delays Friday morning after a man set himself on fire outside the Damen station in Wicker Park, Chicago fire officials said.

The Chicago Fire Department said it responded just after 6 a.m. for a man who set himself on fire outside the Damen stop. CFD said it was not immediately clear if the fire was accidental or purposeful.

The man was taken to Stroger Hospital in critical condition for treatment.

CTA alerted for significant delays on the Blue Line due to the fire department activity, and said that for several hours trains were single-tracking between Western and Damen on the O'Hare branch of the line.

By 9:15 a.m., Forest Park-bound Blue Line trains were running with minor delays, and normal service was resuming.

CBS News Chicago has reached out to Chicago police for more information about this incident and are waiting to hear back.