1 Samuel 4:6-7, 10-11

When the Philistines heard the noise of the shout, they said, “What does the noise of this great shout in the camp of the Hebrews mean?” Then they understood that the ark of the LORD had come into the camp. The Philistines were afraid, for they said, “God has come into the camp.” And they said, “Woe [disaster is coming] to us! For nothing like this has happened before.

So the Philistines fought; Israel was defeated and every man fled to his tent. It was a very great defeat, for thirty thousand foot soldiers of Israel fell. Also the ark of God was taken; and the two sons of Eli, Hophni and Phinehas, were killed. [1 Sam 2:34]