King Family in Accident After Speech Commemoration

Fifty years since "I have a dream..."

Martin Luther King Jr.'s family just got into an auto accident while leaving the rally to commemorate the 50th anniversary of his "I have a dream" speech … TMZ has learned.

According to sources on the scene … several of MLK Jr.'s siblings and grandchildren were on a charter bus leaving the rally when a van ran a red light … forcing the bus driver to slam on the brakes to dodge the vehicle.

MLK's sister—Christine King Farris—was on the bus at the time of the accident. Earlier in the day, the 85-year-old placed a wreath on the MLK Jr. Memorial.