[livius]

These indicate that the pilot reported hitting tropical turbulence at 3am (BST), shortly before reaching Senegalese airspace

It was Senagalese airspace at that point?

In any case, this is a horrible scenario. Prayers for all those poor people.

[ERJCaptain]

It was in international airspace, but in Dakar Oceanic’s ATC sector.

As for the lack of radio transmissions, when you’re over the open ocean, transmissions are done over HF frequencies. HF is somewhat unreliable, so even if they wanted to broadcast a mayday, there is a chance that Dakar wouldn’t hear it.