CHARLOTTE, N.C. — A Charlotte-Mecklenburg Police Department officer was charged with DWI after a crash on Interstate 77 early Saturday morning, according to police.

The rear-end crash involving Officer Marsaun Cook was followed by another collision when a motorist struck three marked police cars of responding officers. The driver of the vehicle in the second crash also was charged with driving while impaired, police said.

No injuries were reported in either collision.

The two crashes took place around 3 a.m. on I-77 South near Arrowood Road, CMPD said in its news release.

Cook, 32, was not on duty at the time of the crashes.

Cook joined CMPD in February 2017 and is a school resource officer assigned to Olympic High School in southwest Charlotte. Police said he has been placed on administrative leave during an internal affairs investigation.

Police Chief Johnny Jennings said in a tweet Saturday morning that he will hold staff accountable for breaking the law or endangering the public. “Unfortunately, our people are not immune to human error,” he stated.

CMPD and the N.C. State Highway Patrol are investigating both crashes.