Israel goes to Bethel to appear before the Lord and to weep, because the tribe of Benjamin has been brought to extinction. This is the very thing they did, twice, during the war against Benjamin (Judges 20:22, Judges 20:26). Except now Israel is weeping not because of failure, but because of success.
2 And the people came to Bethel and sat there till evening before God, and they lifted up their voices and wept bitterly.