Defects found on rail cars for Chicago CHICAGO, March 8 (UPI) -- Defective and potentially dangerous parts from China were installed on new cars manufactured for the Chicago Transit Authority, an investigation revealed. A probe conducted by the CTA discovered that steel parts on the underbelly of the cars could break and lead to a train derailment, the Chicago Tribune reported Thursday. Investigators found inferior craftsmanship on safety-sensitive assemblies that support much of a train's weight. The new cars, known as the 5000 Series, were purchased from the Canadian firm Bombardier Transportation. CTA officials said almost all the failed steel castings were manufactured for Bombardier at the Sifang foundry in Qingdao, China. The factory is no longer working on the CTA contract, officials said. The CTA is the first transit agency to purchase Bombardier's 5000 Series under a contract totaling more than $1 billion for 706 rail cars.