“I’m sick to my stomach about it,” Tanya Stephens, 63, said of the slaying of her 73-year-old uncle, James Lambert, who was attacked by teenage thugs who hit him repeatedly with traffic cones shortly after 3am. on June 14 as he drove down Cecil B. Moore Boulevard. “We all can’t stop crying. Who does this? Any normal person doesn’t hit and kill a senior citizen walking down the street. Simi didn’t deserve this.” Disturbing video of the incident, released by police on Friday, shows Lambert trying to get away from the teenagers as they follow him and beat him to the ground with a cone. He tries to get up and run away, but is hit again while some of the teenagers smile and laugh. Lambert, who had lived in Philadelphia his entire life, was taken to a local hospital where he died the next day from his injuries, police said. The Philadelphia Police Department is offering a $20,000 reward for information about the case. Philadelphia Police Department/Facebook Stephens told The Post that she grew up with several generations of her family, including her uncle, in a large house in the city’s Fairmount. Many family members still live within blocks of each other. Stephens said her uncle, who was retired from construction work, “stepped in” to help her mother care for her and her 10 siblings when Stephens was 12 and her father died. He and his sister, Tanya’s mother Elsie Lambert Stephens, 85, were still so close that “Simmie” often went to her house for dinner. The family gathered every Thanksgiving at Elsie’s house. “Everyone would always ask, where is Simi, has Simi arrived yet?” Stephens recalled. “He just had this buzz, so cool. And she always dressed like she was out of GQ.” Lambert never married and had two daughters and three grandchildren, Stevens said. Overcame heroin addiction in the 1960s. Lambert was at his sister Elsie’s house for dinner a few hours before he was attacked. “My mom gave him his plate,” Stephens said. “She gave him roast chicken, some mac and cheese and a roll for dinner. He said to him, you are late, there are no sides left. Lambert’s niece, Tanya Stephens, said she is “sickened” by the crime.NBC10 Philadelphia Stephens doesn’t know why her uncle was out so late, but said his ride was on a route he took often. None of the teenagers seen in the video attacking Lambert had been arrested as of Friday. The Philadelphia Police Department is offering a $20,000 reward for information leading to the culprits. A police spokesman told The Post Saturday there were no new developments in the case. “These guys need to come forward,” Stephens said. “Their parents should come forward. Something is wrong when the kids are out at 2 in the morning and beat and kill an old man. We lost God, we lost family, what happened to us?’