like many this has been on my mind all day!
Was thinking that if there had been a catastrophic mid air explosion, the sky being absolutely cloudless...surely somebody would have seen it? Shipping, fishermen someone taking a walk on the beach from Malaysia/Thailand to Vietnam..lots of navy(s) posturing activity in S China sea at present too?
Hell even my wife or I may have seen it if we were out on the veranda ... we view from NNW to SSE from about 300m above sea level...bit ghoulish to do the spherical trig ..but if it was at about 30kft it is likely...
very sad and upsetting this....