(CBS) – A CTA bus driver is recovering tonight after being robbed on the job by a man using a stun gun.

The crime might have gone unnoticed for hours if it wasn’t for a Good Samaritan walking by.

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CBS 2’s Mai Martinez reports.

“Before I got on the bus, I could see her kind of laying down, so I was like, ‘What happened?’” Konetheian Sims says.

He is talking about the CTA bus driver he found slumped over behind the wheel of a No. 126 Jackson bus around 7:30 Saturday morning.

“I just called out her name like ‘Excuse me, are you OK?’, and she didn’t respond, so I called the police.”

As he waited for police, Sims flagged down a passing CTA bus. That bus’s driver and Sims both tried help the victim.

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“Her eyes were blinking really fast, so I was thinking well, maybe she passed out, maybe she had a seizure or something,” Sims says.

When the injured driver was finally able to talk, she said she had been “tased” three times, he says.

The driver later told police she was driving west on Jackson Boulevard when she picked up a male passenger. A few blocks later, he demanded to be let off.

When the driver stopped in the 5900 block of Jackson, she says he stunned her with a stun gun several times, went through her pockets and stole her money before fleeing.

Sims says he’s just grateful he was able to help the woman.

Chicago Police are reviewing video from the CTA to see if there is an image of the man.

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The driver is doing OK, saying she’s considering legal action against the CTA. A CTA spokesperson declined comment on the case but said drivers have been told about the attack and warned to be on alert.