1 Chronicles 10:6 (KJV)

Then said Saul to his armourbearer, Draw thy sword, and thrust me through therewith; lest these uncircumcised come and abuse me. But his armourbearer would not; for he was sore afraid. So Saul took a sword, and fell upon it.

And when his armourbearer saw that Saul was dead, he fell likewise on the sword, and died.

So Saul died, and his three sons, and all his house died together.

And when all the men of Israel that were in the valley saw that they fled, and that Saul and his sons were dead, then they forsook their cities, and fled: and the Philistines came and dwelt in them.

And it came to pass on the morrow, when the Philistines came to strip the slain, that they found Saul and his sons fallen in mount Gilboa.