Simplify the following text for a Grade 11 native English-speaking person.
Original: Partly in response to the Sharpeville Massacre of 1960 , individual members of the ANC found it necessary to consider violence to combat what passive protest had failed to quell .
Simplified: Partly in response to the Sharpeville Massacre of 1960 , individual members of the ANC thought violence was needed because peaceful passive protest had failed .