We don't know who struck first, us or them. But we do know it was us that scorched the sky. At the time, they were dependent on solar power. It was believed they would be unable to survive without an energy source as abundant as the sun.
Trinity: Neo, I'm not afraid anymore. The Oracle told me that I would fall in love and that that man... the man that I loved would be The One. So you see, you can't be dead. You can't be... because I love you. You hear me? I love you. [Trinity kisses Neo; Neo's vital signs return] Trinity: Now get up!