A runaway train. Passengers on a boston bway are horrified to find no operator onboard as the train speeds through station nightly news begins good evening. For much of the afternoon, our eyes have been closely trained o a lake near the scene of the San Bernardino terror massacre where fbi divers have been engaged in a new evidence, one Authorities Say could go on for days. In addition to tracking the physical and digital trail of this husband and wife team of killers, weve learned investigators are also now taking a harder look at the couples family tree, after discovering some relationships that raise nude questions about them and those close to them. Heres nbc Miguel Almaguer with late details. Reporter today the fbi sent divers to miles from where the ooting took place. Authorities say it wasinrelated to their investigation, but declined to say how. We are seeking evidence of any sting that had to do with this particular crime. Rmeomter investigators continue enrique marquez. Offic