Sasaki analyzed the situation in the blink of an eye.
The fire was coming from three sources. One on the top floor, one in the staircase and the last in the entrance.
The building's air conditioning was blowing the smoke upwards through the building and made it look like the fire was coming from the roof.

Mr. Aizawa had said there were 10 "people" still inside the building. She'd guess there were 2 on each. It would make the most sense for this sort of exercise.

Including her there were 13 people left in her class. Two of them had at least partial control of air, one had a water based quirk and another one could control small fires.

Then there was a bulky girl with skin made from heat resistant stone and another boy who could make transparent shields.

The last people with useful quirks were two girls with telekinesis quirks.

With the situation analysed and a solution found Sasaki turned to the rest of the hero students.

They were panicking like headless chicken. Even a low-ranking handyman in the mafia could have figured out a plan by now. Or they'd have started doing something without a plan. But they would never freeze like the other students did.

"I have a plan," her voice cut through the panicked chatter.
All eyes turned to her.
"There are three seperate fires. One on the groundfloor, another in the staircase at about the third floor and the last is on the highest floor. The smoke on the roof is because of the air conditioning. There-"

"How do you know that. You're just guessing," the boy with the shield quirk shouted from the back.

She glared.
"I wasn't finished. Don't interrupt me."
With that she continued.
"There are 10 victims, likely one on each floor. We build three teams. One team consisting of you five"
she pointed at the student with the air quirk, the one who could control water, the rude one, the fire one and the girl with the stone skin
",go ahead of us and extinguish all the fires you come across."

"If you see a victim you can alert us by shouting. The other team consists of the two of you and you over there,"
she nodded towards the girls with telekenisis and the remaining one with the air quirk
",are the most important here. You can blow any smoke out of our way and you can transport any injured victims. And you with the headphones can alert us of anything the first team says."

"The rest of us deal with any debris or structual damage to the building. We either stay behind and make sure that the rescue team can get the victims out or we follow slightly after the extinguishing team to clear the way and inspect the building. If we do this the likelihood-"

"Like fuck. Why would I listen to you? You aren't our leader!" the boy with the shield quirk shouted again.

"Yeah, don't be so pretentious. Do you think you are better than us? I don't need your plan!"

"I don't like Sasaki, but I think her plan makes sense," one of the students with the air quirk spoke up.

"She is pretty weird and yeah, she acts like we're inferior but you have to admit that we have no idea what to do. We were just standing around while she was making plans," the boy with the headphones spoke.

"Fuck this." shield-boy shouted. He ran into the building, the second one followed closely behind.

Sasaki took a calming breath. Depending on the mission such an act of insubordination and sheer stupidity would have given you nothing but a broken jaw and three bullets to the chest.
She absolutely despised the individualism the hero industry shoved down the throats of its consumers.
No one in the mafia trusted each other but at least they knew when to follow orders and how to rely on each other on missions. They could work together even while hating each others' guts. The students wouldn't survive half a day in Yokohama behaving like that.

"We can still follow the plan without them. It will be harder and more dangerous but it is doable."

A ripple of excitement and determination went through the class.
"Let's do this!"
"Yeah, go beyond!"
"Plus Ultra," the rest of the class joined in.
They were wasting time.

For a group of amateurs Sasaki had to say that they weren't half bad. What they lacked in skill they partially made up in enthusiasm. If the fire had been real that wouldn't have been enough Sasaki knew though.

Besides shield-boy and the other one everyone did their job. The got the victims out in 10 minutes, without any "death" and only some coughs and minor burns. The fires had been extinguished after 12 minutes.
It could have been better. But all in all Sasaki was satisfied.

Mr. Aizawa agreed with her assessment in the discussion afterwards.

"Sasaki's plan was smart. There were a few flaws but even pros can't avoid those."

Smiles decorated the faces of most of the students. They weren't used to praise from him. But Sasaki could predict what Aizawa was going to say next. Just as she could predict who would still be here by the end of the day.

"In real life however, there would have been casualties. Some of you treated this like a game. You didn't check for structual damage and you treated the "victims" like ragdolls."

Slowly the smiles were melting of their faces. Sasaki remained impassive. She knew this would happen and recognized that the mission would have been a disaster in real life.

"Let me reitarate. Those of you who don't take this seriously, those of you who don't listen and who refuse to cooperate have no place in this class. Teamwork is a fundamental pillar of being a hero. Without that you don't have any right to be here, do you understand, Himura, Ishioka?"

Mr. Aizawa's gaze settled heavily on shield-boy and the other one.

"What?" Himura squeaked

"You are expelled. Go to Nedzu's office and tell him."

There was spite and shame in their eyes. When they walked to the changing rooms they purposefully shoved past her. Sasaki didn't budge.

She agreed with Mr. Aizawa's words. They didn't fit into a hero class. They wouldn't last an hour in the field. Begrudgingly her opinion of him rose again. She didn't expect a hero like him to be so honset and perceptive. She should have realized that Aizawa wasn't like the other heroes earlier.

He turned again to the rest of the class. His eyes swept over them. They seemed to linger a bit longer on Sasaki. She straightened unintentionally. Her chin tilted upwards with defiance.

A sigh.
"You can go now. And remember teamwork is important."

This time she didn't feel him watching her leave. Sasaki suspected he just couldn't see her through the rest of the students.