CNN CNN International May 16, 2015 07:12:00
>> interesting to note. u.s. safety authorities are in the process of implementing an ought matting speed control system on rail lines. that technology called positive train control was supposed to be in place by the end of 2015. the stretch of track where this crash occurred did not have it installed offs yet. u.k. rails meantime are operating a lower tech version of this kind of braking system. later in the show, phil black will explain exactly how it works. yes has taken control over government buildings from iraqi forces in ramadi. [ gunfire ] >> big push for the key city started thursda...