At the end of chapter 3, as Nick is leaving Gatsby's party he sees a "bizarre and tumultuous scene," lit up by "a dozen headlights" from other cars. The adjectives "bizarre" and "tumultuous" at once indicate that there is something strange about the car crash, and also that it is a chaotic scene. Nick then describes the car as having been "violently shorn of one wheel." The adverb "violently" suggests that the impact of the crash must have been especially severe. The suggestion is that the wheel has been torn clean off from the body of the car.
Nick also describes a "harsh discordant din" emanating from the people gathered at the scene of the crash, which he says adds to the "already violent confusion of the scene." The adjectives "harsh" and "discordant" suggest that the people are perhaps arguing and shouting over one another. The adjective "violent" to describe the confusion suggests a chaotic scene.
The strangeness of the car crash is mostly conveyed through the reaction of the the man who "dismount(s) from the crashed car. When he emerges from the car, he looks around at the people in "a pleasant, puzzled way." The adjectives "pleasant" and "puzzled" suggest that this man, known as Owl Eyes, does not understand or appreciate the seriousness of the situation. One might expect someone emerging from a car crash to be shaking and scared, but one would certainly not expect that person to be "pleasant" and "puzzled." This very strange reaction suggests that either the car crash was not as serious and severe as the noise and the reactions of the people might suggest, or that Owl Eyes is perhaps too intoxicated to realize what has happened.