In an interview yesterday, his mother said that Kless had been excited to be back in Philly - back near his friends, and starting a new job.
The youngest of three brothers from Warwick, Orange County, N.Y., he had been working at an insurance firm in Harrisburg after graduating from Temple in 2010, then got a job with the Philadelphia office of Marsh, the world's largest insurance broker.
"He was really happy," his mother, Kendall, said by phone from Warwick, breaking down in tears. "He was happy to be back around his Temple friends. He has a ton of friends. Kevin was a fun-loving, happy-spirited kid."
They last saw each other when he was home for Christmas. "He wanted new clothes for his new job," his mother said.
At 2:25 a.m. Saturday, police said, Kless was walking on Chestnut Street in the historic district with a woman he'd recently begun dating and another female friend, after leaving Lucy's Hat Shop, a bar on Market Street in Old City. They tried to hail a cab.
A taxi came by with its light on, indicating that it was available. But it had passengers. A frustrated Kless, police investigators said, shouted to the driver something like, "Why is your f---ing light on?" or "Turn off your f---ing light!"
The cabbie stopped just long enough for Kless to yell at him, investigators said, when another car pulled up behind the cab. As Kless was arguing with the cabbie, the occupants of the other car - four men in their 20s - tried to pick up the two women, police said.
Three occupants in the car, who might have thought Kless was yelling at them, then got out of the car "and just bee-lined at Kless and just started hitting him," a police source close to the investigation told the Daily News.
The assailants kept swinging at Kless, beating and kicking him in front of the bank, police said. Investigators yesterday said that it was not clear if the assailants had smashed Kless' head against the marble wall in front of the bank, or if he had fallen and banged his head against it. In any case, he was knocked unconscious, and his assailants drove away.
As the two women began screaming, private security guards in front of Independence Hall, on Chestnut between 5th and 6th, heard them. But because they were not permitted to leave their posts, they called National Park Service rangers, four of whom responded and administered first aid, police said.
Philly police soon arrived. Kless was taken to Thomas Jefferson University Hospital in critical condition. He died there at 7:10 that night.
For Kless, moving back to Philly was intended to be an adventure of a happier sort.
He had just moved with a friend who also had graduated from Temple into a three-story, gray-painted brick rowhouse on Brown Street near 16th, in Francisville. No one answered the door at the building yesterday, and neighbors did not recognize Kless from a photo.
By all accounts, he had a promising career ahead of him.
He began working at Marsh's Logan Square office Dec. 5 as a senior broker representative in environmental practice.
At Temple's Fox School of Business, he'd been a student in the department of risk, insurance and health-care management. He was a member of Gamma Iota Sigma, a professional fraternity for students in the insurance field.
The chairman of the department, R.B. Drennan, who had Kless in two classes and knew him through the fraternity, said he "was a good student" and "was well on his way to a very successful career." Kless was "really easy-going, very friendly," Drennan said.
Kless' mother said that he had played varsity baseball in high school and loved disc golf and snowboarding.
In an April 2009 YouTube video, Kless was interviewed by a woman named Beth. The text under the video called Kless "the star of MTV's hit reality show 'The Boy Who Couldn't' " and said that he was going on a national collegiate tour.
"He will be giving motivational speeches to students consisting of true and hilarious stories demonstrating his lifelong streak of bad luck," the YouTube site said. "These speeches will entertain and motivate students to see that life is never as bad as it seems."
Kless' mother said she thought that the video might have been for a Temple class and that he hadn't actually been on MTV and hadn't gone on a national tour.
"I think it was just him doing his Kevin thing - he was such a jokester," she said. "He had such a sense of humor. Everyone would tell you he made everyone laugh."
But there was no laughter on Saturday, when Kendall Kless received "the worst call you ever expect in your life, the call no parent ever wants, ever," she told the Daily News yesterday. She rushed to Jefferson along with Kevin's father, John; Kevin's two brothers, Matt and Tim; and other family members.
Investigators yesterday described the assailants as having "olive-toned" skin. Although police initially put out a description of their car, investigators yesterday cautioned that images from grainy surveillance video in the area did not clearly show the color or model of the car. Police hope to distribute a clear image today.
Jane Cowley, a spokeswoman for Independence National Historical Park, said that surveillance cameras are situated throughout the historic district, but she could not say where.
Police said the former bank building, administered by the National Park Service, does not have outside surveillance cameras.
The Omni Hotel, across the street, also does not have cameras outside on Chestnut, and none of its staff was outside when the attack occurred, the hotel's general manager, A.J. Williams, said yesterday. A worker in a small shop next to the hotel said the business there also doesn't have an outside surveillance camera.
Tipsters should call Philly detectives at 215-686-3334 or 9-1-1.
"I need help," said Kendall Kless, the grieving mother. "I'm burying my 23-year-old son, and I shouldn't have to."