CHICAGO (CBS) – There are serious questions about whether a CTA bus, that crashed and injured more than 30 passengers, was properly serviced and maintained.

The crash happened Saturday night on Lake Shore Drive, just south of McCormick Place. The bus veered off the roadway and crashed into a tree. What caused it? CBS 2’s Mike Parker has a possible answer.

The “smoking gun” may be the CTA maintenance and service record of the bus that crashed. It may provide the reason the steering wheel on the vehicle suddenly froze, the reason why the driver could not keep the bus on the road.

Yolanda Anderson was one of those hurt in the accident. She suffered injuries to her neck, back and arms, and possible nerve damage.

She says she first noticed that the steering wheel “was going over to the right and I just asked the question out loud, ‘what’s going on?’ And we jumped the curb and we just went flying through the trees.”

Anderson is the first of the crash victims on the #6 Jackson Park Express to file suit against the CTA, charging negligence.

The bus’ inspection and maintenance record may provide a clue. Although the preventive maintenance schedule calls for the front wheel bearings to be repacked or lubricated at 45,000 miles, the document says that when the bus was inspected September 17th, there were more than 63,000 miles on the odometer and the repacking was still not done.

CTA drivers say the front wheel bearings are crucial to the steering mechanisms on these giant vehicles.

We showed the report to Larry Rogers, the attorney representing Yolanda Anderson.

“There’s a reason why they have those preventive maintenance programs, and one of the reasons is to make sure that the bus operates properly and is in a safe condition,” said Rogers.

Anderson reacted strongly.

“That means they put all our lives at risk, and everyone that was on Lake Shore Drive,” she said.

The CTA is suggesting that, despite what the document seems to show, work on the bearings is not mandatory. In a written statement, the CTA said: “The bus had its components inspected in mid-September, including the bearings, and the bus passed inspection.”

The CTA says it inspects buses every 5,000, and that any bus that does not pass is either fixed or taken off the road.

That’s the policy. Was it followed in this case? We don’t know.

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