J ust to complement what has just been said,
watch out Ioco not to jump to conclusions too hastily.
30 to 40 NM is correct IF the display was set up that way, and if it was the other a/c only appears as a symbol of info, i.e. not to be reacted upon.
Also I doubt very much that the crews were glued to their TCAS screen, as there was no reason at this place, time and Altitude to keep watching the TCAS screen.
The real warning, with an audio, came much, much later. The CVR tapes will tell you exactly how much.
You will know by early next week, as the tapes are damaged and need repair before being exploited.. My sincere condoleances for your loss.