A report released on Thursday revealed that new train cars manufactured for the Chicago Transit Authority were made with faulty and potentially hazardous materials from China.

According to the investigation, substandard steel parts on the undercarriage of the CTA rail cars could disintegrate and result in derailment.

The new train cars, known as the "5000 Series," were purchased from Bombardier Transportation, a firm based in Canada.

Almost all of the faulty steel castings were produced by Sifang Foundry in Qingdao, China. for Bombardier, CTA officials revealed.