A Maryland teacher was sideswiped and killed by a Maryland State Police cadet on the Capital Beltway Friday morning.

On a routine assignment shortly after 8:30 a.m., 18-year-old Cadet Sebastian L. Reyes, driving an unmarked SUV without lights or siren activated, apparently used a crossover for emergency vehicles to access the Outer Loop from the Inner Loop south of Route 50, police said.

He sideswiped a Lincoln, sending it into a jersey wall and causing his SUV to spin and strike a Subaru Outback.

The driver of the Lincoln, 59-year-old Karen Holt-Williams of Temple Hills, was taken to Prince George’s Hospital Center where she was pronounced dead.

"She was a nice person," neighbor Vanessa Watson said. "I always enjoyed being around her."

Holt-Williams' neighbors say she had been teaching in the area for more than a decade, and on the morning of the crash, she was on her way to get her teaching recertification. She had five children and four grandchildren.

The driver and two passengers in the Subaru Outback were not injured. Reyes and another cadet riding with him refused treatment.

Reyes, a civilian employee with the commercial vehicle enforcement division, was placed on leave.

"As a cadet, as a civilian employee, he does not have any police authority [to make that turn], so that's something the investigators will be looking at," Greg Shipley with Maryland State Police said.