Normal service resumes after Loop CTA switching problems

CHICAGO (WLS) -- Green, Orange, Brown, Purple and Pink Line trains have resumed normal service to the Loop after earlier switching problems.

Loop-bound Brown and Purple line trains were holding at Merchandise Mart around 8:45 a.m. due to signal problems at Clark/Lake, the CTA tweeted.

Brown line trains used Orange line tracks and Purple Line trains were rerouted onto the Red Line subway tracks.

CTA has not said what caused the signal and switching problems.