We know there has been a Battle between Marines and another unknown opposing force!!
apparently the Sailors got the worst of this clash... as it shows several dead sailors beside Bell-mère who is also about to die!!
She meets 2 Girls (Nami and Nojiko) and gets back to live again after seeing Nami's SMILE!!
She curiously takes a small boat and runs away from that Island and goes towards East Blue taking the 2 children in the middle of a storm!!
The question is... why Bell-mère as the only possible survivor of that conflict didn't take the 2 Children to the Navy HQ (which has a whole health system with trained doctors) and report the situation of Gueera to his superiors? instead she ran away taking 2 kids from that suspicious town and hid them in East Blue?!
Probably Nami or her family had some connection with that insidente (who maybe has some connection with the lost century), and Bell-Mère decided not to take these children to the Navy fearing for their deaths !!
Maybe Oda will still bring some development in relation to Nami... maybe Nami's Family is one of the only ones who know how to use Uranus and for that reason there was a War!!