CHICAGO (CBS) — CTA Red Line trains were snagged on the South Side due to debris on the tracks Tuesday afternoon.

The Chicago Transit Authority said by 4:20 p.m., trains were running as usual, but with residual delays and more congestion than usual.

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Earlier, trains had been running in two sections – between Howard and 47th, and between 47th and 95th, with limited service on the southerly leg. Commuters had to change trains at 47th for continuing service to 95th.

Earlier still, all service was suspended from Roosevelt to 95th, and trains were only running above Roosevelt.

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The CTA originally said the trains were stopped due to what the agency only called an “incident,” but later clarified that debris on the tracks at 63rd Street was to blame.

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The CTA said earlier that there was an incident at the 63rd Street stop that earlier halted service.

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The agency advised considering other alternatives for transportation such as nearby bus routes.