Simplify the following text for a Grade 8 native English-speaking person.
Original: His father 's death in June 1957 affected Chandler so much that he jumped into the open grave at the funeral as the gravediggers were covering the coffin with dirt .
Simplified: This upset Oba so much that he jumped into his father 's grave during the funeral in 1957 while gravediggers were covering the coffin with dirt .