Tesla to retrofit 16,000 cars to reduce the risk of a fire in a crash

The automaker plans to reinforce the undercarriage of its Model S sports sedans with high-strength shields, a move that ends a probe into two fires that occurred in the electric cars.Tesla Motors Inc. has announced plans to reinforce the undercarriage of about 16,000 cars with high-strength shields to reduce the risk of damage from a crash starting a fire.