Who was responsible for the "four little girls" bombing?

it would be  

germany had to pay all damages related to the war.

and i think

germany had to take sole responsibility for the war.

although world war i began in 1914, the united states did not join the war until 1917. the additional firepower, resources, and soldiers of the u.s. to tip the balance of the war in favor of the allies. remaining neutral. when war broke out in 1914, the united states had a policy of neutrality.