jon: doctor alan diehl, it's good to have your expertise, thank you. >> thank you john. melissa: the presumptive republican nominee donald trump also weighing in on this tragedy. chief political correspondent donald cameron is live in new jersey with the details. hi carl. reporter: it is rare for a presidential candidate to weigh in on such things before we've actually gotten an official word from the authorities doing investigations but long before the french and egyptian governments began to suggest that perhaps there was a terrorist attack that led to the downing of flight 804, donald trump on twitter speculated that in fact it was. he said it looks like yet another terrorist attack. airplane departed from paris. when will we get tough, smart and vigilant? great hate and sickness. trump has been criticized for being occasionally premature with his tweeting and weighing in on things that could be politically dangerous. this was treated long before the french president suggested that terrorism had to be considered at least one egyptian official said that was a possibili

alan diehl speaking with me earlier.t's look a little more closely at flight data recorders, black boxes the commonly used name for them. but the units aren't actually black. most of us know by now they're orange to make them easier to spot in wreckage. the data recorders are located in the tail of the plane where they're less likely to be damaged by an impact. they recorder technical information from a flight, things like altitude, air speed, and heading, as well as audio from the cockpit and the engines. two recorders for voice and data can be combined in a single unit. to help search teams find them, flight data recorders send out a homing signal for up to 30 days after a crash. that radio ping can be detected even when it's being sent from more than 4,000 meters. that's more than 13,000 feet underwater. well, search teams have yet to find the data recorders for this flight or much else at this point. even small pieces of debris could be instrumental to figuring out what happened to the downed plane. forensics teams a