CHICAGO (CBS) — Service on the CTA Blue Line was briefly halted near the Clark/Lake stop downtown Tuesday night due to an unauthorized person on the tracks.

The Fire Department said the man who had been on the tracks was taken to Northwestern Memorial Hospital in fair-to-serious condition.

Service had resumed by 9:30 p.m.

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This was the second delay on the Blue Line caused by someone getting onto the tracks within a matter of hours Tuesday.

The Fire Department said in the late afternoon, a man had a medical episode that caused him to fall on the tracks near the Jackson stop downtown. He was taken to Northwestern Memorial Hospital in serious, but stable condition, the Fire Department said.

That led the Chicago Transit Authority to shut down the Blue Line from the Damen stop in Wicker Park to the Racine stop on the Near West Side.

On Monday afternoon, the Blue Line was also shut down between Damen and Racine — though that time, it was smoke near the Jackson stop to blame.