SEAL BEACH, Calif. (KABC) -- A father and child are dead after a crash on the 405 Freeway near Seal Beach, which prompted the closure of several lanes and led to major morning traffic congestion.The crash, involving a Honda CRV and Toyota Rav4, happened about 2:30 a.m. Friday just north of the Seal Beach Boulevard exit.California Highway Patrol authorities said they believe the CRV stalled in lanes with members of a family inside. A father and small child got out of the vehicle and were struck by the oncoming Rav4.The father and child, believed to be his son, were killed. Two other members of the family inside the vehicle were rushed to a nearby hospital in critical condition, as well as an occupant from the Rav4, according to CHP Officer Duane Graham.The carpool and No. 1 through 4 lanes were blocked for several hours, which led to a serious backup for commuters on the already-congested freeway.All lanes were back open shortly before 7 a.m.An investigation into the fatal crash was ongoing.Authorities underlined the importance of staying in your car if it stalls on the freeway."The cars are traveling out here on the freeway are traveling at a high rates of speeds. Depending on the lighting conditions, if it's dark or what have you, it's very dangerous to be outside of your vehicle on a highway," CHP officials said.