The Metropolitan Police Department is investigating the death of a Maryland man who died Monday afternoon after being arrested following a traffic accident at Union Station.

According to MPD officials, Gary Thompson, 37, was involved in a “minor traffic accident” at Columbus Circle and E Street Northeast at noon.

A Capitol Police officer on routine patrol witnessed the accident — involving a taxi and a van owned by Virginia-based Refrigeration Systems Inc. that Thompson was driving — and responded to assist with the incident.

“At some point the driver of the van reportedly began acting somewhat irrational and was removed from the van,” according to a statement issued by MPD. Thompson then became “combative and a struggle ensued.”

Police subdued and handcuffed Thompson, who then fell unconscious. He was transported to Washington Hospital Center, where he was pronounced dead at 12:59 p.m.

Capitol Police are assisting with the investigation, but a spokeswoman directed all questions about the incident to MPD.

“The Capitol Police want to express our sincere condolences to the family of the deceased,” said Sgt. Contricia Sellers-Ford, a Capitol Police spokeswoman.

MPD’s violent crimes branch is investigating the incident. No cause of death had been determined early Monday evening.