Oncoming traffic attempted to dodge Heitmann, but he collided with a 2010 Kia minivan occupied by 43-year-old Aileen Pizarro and her 12-year-old daughter Aryana.
Mr Heitmann, 18, was travelling southbound in a northbound lane of the Interstate-805 Freeway near San Diego in California when the crash happened about 4.30pm (local time) on Thursday.
YouTuber Trevor Heitman, 18, who rose to internet fame under the name "McSkillet" by posting videos about video gaming and gambling, smashed his McLaren 650S sports vehicle into an SUV on Thursday, according to the San Diego Union-Tribune.
"At the time of the crash, he could have been going over 100 miles per hour", CHP Officer Jake Sanchez told the newspaper.
Heitmann's neighbors told KSWB they saw San Diego police at his house Thursday.
Under the online moniker McSkillet, Heitmann had been a successful YouTuber, with some of his CS:GO-related videos amassing millions of views. In December, he posted a video of the McLaren he bought, explaining that he used funds from skin trading and monetizing YouTube videos. A spokesperson for the San Diego County Department of Public Safety confirmed the driver involved in the crash was Trevor Heitmann. Police had responded to Heitmann's home in Sea Knoll Court earlier Thursday after his dad said the teen sped off, hitting another auto; seems Heitmann then smashed through the gate of an elementary school and broke a window before driving away, per Fox 5.
Heitmann, who was also heavily involved in the CounterStrike gambling scene, made headlines in 2016 after he posted an April Fool's joke video that led to major swings on the game's marketplace. Witnesses saw the driver hit the gate, then get out of the vehicle to break a school window.
"I was anxious he was going to hit the two people standing at the gate", witness Alec Galloway told Fox 5 San Diego.