Despite the fact that it was in Nigeria I think the facts will be known, as the operating company was the reputable Aero Contractors Nigeria and this is their first fatal helicopter accident for over 20 years. The accident happened in daylight, VMC and the aircraft ended up in the water alongside the helipad at Brass Oil Terminal on the coast of the Niger Delta. As, so sadly, both of the crew have died, it may take longer to find out the actual cause, but the aircraft was fitted with a CVR. At the moment, anything further is speculation as this early on in the proceedings there is still quite a lot of confusion.