Lotta explosions in east asia.
I'm thinking that North Korea has activated their spy network to plant explosives. Retaliation for the artillery exchange on the DMZ. Lil Kimmie can't escalate on the border without a major risk of full-scale war... but planted explosives? Who knows?
(NK has a history of this sort of thing. I mean, who sunk the Choenan? An old mine? A torpedo? An accident in the ship's magazine? Sure, SK found torpedo remains... but they're just 'fakes', doncha know.)