LAS VEGAS (KLAS) — Exclusive video obtained by 8 News Now in Las Vegas shows reactions from students the moment a local teacher reportedly wrote a racial slur on a whiteboard.

The Clark County School District acted swiftly to fire the substitute teacher less than 24 hours after the incident occurred. It happened on Tuesday at Silvestri Junior High School.

In one of the video clips, the substitute appears to tell students, “African features … were said to resemble those of monkeys and apes.”

As the lesson continues, the “n” word appears on the whiteboard, and the students react.

“Either we can have a fun class today where we actually talk about English…I was planning on y’all being a bunch of little punks and misbehaving and this class acting as detention,” the substitute is heard saying over the video.

In another clip recorded by students, the teacher writes the slur again on the whiteboard, sparking pushback from kids.

“I don’t know why all of you are making such a big deal when this word leaves most of your mouths every second,” the teacher said.

Out of 40,000 employees at CCSD, 3,400 are substitute teachers. They are required to have a teaching license and get a background check.

According to a district handbook, substitute teachers must follow the lesson plans teachers leave behind. If there isn’t one, substitutes must talk to an administrator.

8 News Now isn’t identifying the teacher since he wasn’t charged with a crime. State records show he received his teaching license in January.

The district told 8 News Now in part:

“… In general, day-to-day substitutes are provided with lesson plans by the school. Vacancy or long-term substitutes create lesson plans with guidance from school administration.

All teachers, including substitutes, must go through the process of obtaining a license from the Nevada Department of Education before they are hired.“

In a letter sent to parents, Silvestri Junior High School’s principal said actions like the one by the substitute won’t be tolerated.