One person was critically injured Monday afternoon in an accident involving a car and a truck near Nationals Park in southwest Washington, according to D.C. police.

Police said at least one person was ejected from a vehicle and taken to an area hospital in critical condition. The department’s Major Crash Unit, which handles accidents with serious injuries and death, is investigating.

Authorities provided few immediate details. They said the accident occurred shortly after 3 p.m. at South Capitol and M streets.

Backups were reported on the Douglas Bridge, which was reopened at Potomac Street about 4 p.m. The underpass at South Capitol and M streets remained closed at 4 p.m.