Boy's last words: 'What's going on?' Suburban mom held after children stabbed 500 times

They moved here with a mission -- to build a Christian communityfor Bulgarians who had settled in Chicago.

Nikolai Vasilev was the pastor and his wife, Tonya, was the Sundayschool teacher. Together they nurtured an evangelical community inthe northwest suburbs and created their own family. They had threechildren and survived the death of one of them in a 2000 fire.

Wednesday night, Nikolai came home to find his two remainingchildren, a 9-year-old son and 3-year-old daughter, stabbed to death -- some 500 times -- and his wife bathed in blood, a source close tothe investigation said.

Tonya Vasilev, 34, has given statements to Hoffman Estates policeand was …