The greatest army in the world, camped around one small city.
וְגַנּוֹתִי אֶל הָעִיר הַזֹּאת לְהוֹשִׁיעָהּ לְמַעֲנִי וּלְמַעַן דָּוִד עַבְדִּי׃
מלכים ב יט:לד
"For I will shield this city to save it, for My own sake and for the sake of Dovid My servant."
Melachim Beis 19:34
That night, someone walked through the camp.
וַיְהִי בַּלַּיְלָה הַהוּא וַיֵּצֵא מַלְאַךְ ה' וַיַּךְ בְּמַחֲנֵה אַשּׁוּר מֵאָה שְׁמוֹנִים וַחֲמִשָּׁה אָלֶף׃
מלכים ב יט:לה
"And it was on that night that the angel of Hashem went out, and struck in the camp of Ashur one hundred and eighty-five thousand."
Melachim Beis 19:35
In the morning, nobody got up.
וַיַּשְׁכִּימוּ בַבֹּקֶר וְהִנֵּה כֻלָּם פְּגָרִים מֵתִים׃
מלכים ב יט:לה
"And they rose early in the morning, and behold, they were all dead."
Melachim Beis 19:35