188 engineer brandon bostian moments before last year s tragic crash in port richmond. train experts we spoke to said radio interference has always been a problem. certainly it could have contributed to this accident. but nevertheless, it could have been preventable. reporter: but washington, d.c., rail safety expert larry mann says two things could have saved eight lives and kept hundreds of others unharmed. a second person helping in the locomotive to monitor the dispatch radio and positive train control. had there been positive train control along that route, this accident would have never occurred. reporter: mann says positive train control would stop the train if it was exceeding the speed limit. amtrak 188 was going 106 miles per hour when it hit the curb at frankford junction more than twice the limit. former ntsb chairman james hall says no matter the cause, he hopes amtrak takes steps to become safer. unfortunately just provides interference and a distracti