All lanes of the outbound Stevenson Expressway were blocked this morning following a fatal accident. Authorities say a man rear-ended an IDOT truck around 2:00 a.m. after the IDOT truck was helping another vehicle on the Stevenson near Pulaski Road. The victim, who has not been identified, was pronounced dead at Mount Sinai Hospital. Lanes on the southbound portion of the highway were re-opened at around 6:00 this morning.