Just after the start of the fire…

"Hey! What are you doing with that?!" Hiro cried, seeing Professor Callaghan with the controller for his microbots.

Professor Callaghan frowned, noticing Hiro running towards him. It seemed the fire slowly growing around them didn't even faze the boy.

The microbots built a wall around Professor Callaghan and Hiro, soon blocking out the heat and light from the fire. Professor Callaghan grabbed Hiro with the microbots. The microbots covered the boy's mouth and wrapped around his arms and torso before lifting him off the ground.

Hiro shouted at the professor through his makeshift gag. His eyes were blazing with anger, but also with a tiny bit of fear.

"Now, now. Quiet down, Hiro. You don't want to die in the fire now, do you?" Professor Callaghan smirked.

Hiro growled, but was unable to do anything to stop the professor.

"All will be clear in time, Hiro. I want to thank you for the microbots. They'll make my mission a whole lot easier." Professor Callaghan said. "Now. We'd best get out of here before the building turns to ashes. It'd be too easy to find us if that were to happen."

The fear in Hiro's eyes grew a little, but he hid it with anger. He could feel the microbots moving the two of them. Callaghan was probably navigating them out of the fire.

Hiro remembered how he'd been joking with Tadashi earlier that evening, before going back into the Exhibition Hall to get the controller for his microbots. A silent tear slid down his cheek as he hoped Tadashi was okay and hadn't come into the fire after him.

Meanwhile…

Tadashi ran up the steps to the Exhibition Hall, Hiro's jacket in his hand. Hiro was still in there. He had to save him.

He'd almost made it to the door when a huge explosion blasted him away from the building.

When he woke up from the impact, the doors were completely covered in fire. There was no way in.

"HIRO!" He screamed as it registered on his mind that his little brother hadn't made it out of the fire alive.

It seemed like ages before he was able to move and even then it was only because Honey Lemon had come back to check on him. Or rather, to check on him and Hiro.

She let him sob into her shoulder, knowing how much Hiro meant to him and how much the loss hurt. The fire eventually burned itself out. Some students tried to salvage their work, but nothing was left.

Everything was burnt to ashes.