Simplify the following text for a Grade 12 native English-speaking person.
Original: In April 1945 , as Yugoslav Partisans units approached the camp , the UstaÅ e camp supervisors attempted to erase traces of the atrocities by working the death camp at full capacity .
Simplified: In April 1945 , as Partisan units approached the camp , the UstaÅ e camp supervisors attempted to erase traces of the atrocities by working the death camp at full capacity .