11.   Lao said the bus was rounding a curve when its front tires lost traction and it slid off the cliff.

12.   The NHTSA in May began investigating accidents in which Firestone tires suddenly lost their tread or suffered blowouts.

13.   The relationship was strained amid reports last year that some Firestone tires could suddenly lose their tread.

14.   The relationship was strained amid reports that some Firestone tires could suddenly lose their tread.

15.   Tires can lose tread.