I kill ... I wound ... I will make mine arrows drunk with blood, and my sword shall devour flesh. Deuteronomy 32:39-42
In case you haven't been following along, here's what has happened so far in Numbers 16.
Korah and his companions question Moses's leadership, saying "Ye take too much upon you, seeing all the congregation are holy, every one of them, and the LORD is among them: wherefore then lift ye up yourselves above the congregation of the LORD?" (Numbers 16:1-3)
Moses falls on his face. (16:4)
The glory of the Lord appears to the congregation. (16:19)
God tells Moses to get out of the way because he's going to kill everyone. (16:20-21)
Moses and Aaron fall on their faces. (16:22)
Korah, his companions, and their families are buried alive. (16:27-33)
God burns to death 250 men for burning incense. (16:35)
So, as you might expect, the people who had witnessed all this were pretty freaked out by now.
But on the morrow all the congregation of the children of Israel murmured against Moses and against Aaron, saying, Ye have killed the people of the LORD. Numbers 16:41
Then "the glory of the Lord" appeared (again).
Behold ... the glory of the LORD appeared. 16:42
And God tells Moses he's going to kill everyone (again).
And the LORD spake unto Moses, saying, Get you up from among this congregation, that I may consume them as in a moment. 16:44-45a
I think you can guess by now what Moses and Aaron did next.
They fell upon their faces. 16:45b
Then Moses told Aaron to burn some incense to try to stop God from killing everyone.
Moses said unto Aaron, Take a censer, and put fire therein from off the altar, and put on incense, and go quickly unto the congregation, and make an atonement for them: for there is wrath gone out from the LORD; the plague is begun. 16:46
And the incense burning worked. (Sometimes God will stop killing if you burn incense; sometimes he'll burn you to death instead. He works in mysterious ways.) But not before 14,700 had died in the plague.
Now they that died in the plague were fourteen thousand and seven hundred, beside them that died about the matter of Korah. 16:49
So in this chapter (Numbers 16), God threatened to kill everyone twice, but settled for killing 14,959 in three separate killing events (nine or so buried alive, 250 burned to death, and 14,700 killed in a plague).
But don't complain about it or he'll kill you, too.