HIGHLANDS RANCH, Colo. — A driver was arrested for alleged careless driving one week after a crash that killed a Highlands Ranch seventh-grader.

Alexander “Alex” Mackiewicz, 13, was riding a OneWheel (a single-wheel electric skateboard) just before 7 a.m. on March 6 when a driver struck and killed him as he was crossing the intersection of Venneford Ranch Road and Highlands Ranch Parkway.

The driver stayed on the scene after the crash, according to the Douglas County Sheriff’s Office (DCSO).

In an update Wednesday, the sheriff’s office said the driver — identified as Ruben Morones, 52 — was traveling eastbound in the far-right lane on Highlands Ranch Parkway when he approached the intersection. At the time, the signal was red for eastbound traffic, according to the DCSO

Alex was traveling southbound in the crosswalk on Venneford Ranch Road, crossing Highlands Ranch Parkway. The walk signal was activated when the teen was crossing, the sheriff’s office said.

According to DCSO, Morones ran the red light, striking Alex on the opposite side of the intersection. The vehicle came to a “controlled rest” after the impact east of the intersection. Alex was ejected off his Onewheel and came to rest against the curb line east of the intersection, the sheriff’s office said.

Investigators do not believe that speeding was a factor, according to DCSO.

Morones was arrested Wednesday for careless driving causing death, careless driving causing serious bodily injury to a vulnerable road user and failure to obey a traffic control signal.

“This was a tragedy that has impacted not only Alex’s family but the entire Highlands Ranch community. As with any fatal crash, our Office has done a thorough investigation to make sure all the facts are accurate. As the Sheriff, I take traffic safety very seriously, and we will continue to work hard to make our roadways safer through public education and traffic enforcement,” said Sheriff Darren Weekly in a statement.