Aurors and Hit-wizards
Harry was out of bed the moment the fire-message was in the room. Throwing himself onto the watch, he called in the Aurors and made sure Ollerton got the message, then got dressed and used the portkey to transport himself and Ginny to the gates from where they Apparated to Diagon Alley.
The shop was already in flames, and people lay dead on the ground. The building was surrounded, and Harry blasted a hole through the circle of Death Eaters to help George and Fred escape should they still be in the building. Apparating a short distance as the Death Eaters rounded on him, he called out to Ginny: "Keep moving!" He wished she would have stayed at home, but knew enough not to voice it. He shot off another spell, never keepings still long enough for the Death Eaters to have something to hit.