Simplify the following text for a Grade 7 native English-speaking person.
Original: In 415 BC , Athens dispatched a massive expeditionary force to attack Syracuse in Sicily ; the attack failed disastrously , with the destruction of the entire force , in 413 BC .
Simplified: In 415 BC , Athens dispatched a large force to attack Syracuse in Sicily . The attack failed , with the destruction of the entire force , in 413 BC .