Omaha, Neb. — Two people are dead and two others are critically injured after a single-vehicle crash early Saturday morning. The Omaha World-Heraldreports the crash occurred around 3:15 a.m. after a vehicle traveling at a high rate of speed left the roadway. It struck a tree and then hit a retaining wall. Authorities say five people were on board and at least four of them were ejected from the vehicle. Two died at the scene, and two others were transported to the Nebraska Medical Center in critical condition.