A fatal crash in Fairfax County has caused significant traffic delays during Monday’s rush hour, authorities said.

Around 4 p.m., officers arrived at the intersection of Arlington Boulevard and South Street in Falls Church in response to a report of a crash, a spokeswoman for Fairfax County police said. A motorcycle and a motor vehicle had collided, and one person was pronounced dead at the scene, the spokeswoman said.

Further information about the crash was not immediately available, and it was unclear whether the person who was killed was riding the motorcycle or was in the motor vehicle.

Southbound Arlington Boulevard was closed at South Street as accident reconstruction teams responded, according to a tweet from Fairfax County police, and authorities advised commuters to seek alternative routes.