According to the crash report ... the driver told Maryland State Police he was tired and fell asleep. He drifted onto the right shoulder, went off road and struck the tree. The driver told cops he'd recently finished a long shift at work.

We broke the story ... Brandon was riding in the front passenger seat. The driver and another friend, riding in the backseat, survived ... Brandon died from his injuries Sunday in a hospital.

Sources on the scene tell us the driver pulled both passengers out of the car. As we reported ... cops don't think drugs and alcohol played a role.