there were children, and it's really struck a chord in this country, and so, yes, they want to get this -- get some closure on this, but they also want answers. was it terrorism, or was it technical failure? and the investigators have to answer that, john. >> 25 children on board. matthew chance in st. petersburg, thank you so much. let's bring in our aviation expert. cnn safety analyst david soucie, former faa accident investigator and pilot and aviation expert miles o'brien and let's start with the breaking news, the infrared activity, heat flash detected by a u.s. satellite over the sinai peninsula at the time of the incident, what does this mean to you? >> it means a lot of things, and what's most important is did that flash start on the ground, or did it flash happen in the air? very conclusive. if it happened on the ground, it could indicate that there was some sort of missile launched. if it happened in the air, that means there may have been something on the aircraft as far as incendiary devices are and those are really important points so we'll look forward to