The garden Leeto Ly planted after his father died is blooming this year stronger than ever.

The peonies have been bursting into bloom, some with scents more vivid than they've ever had before. It's one small happiness for his mother, he said, who is still mourning her husband's murder.

"My mother picks the flowers, and it takes away her grief," said Leeto, 36.

That grief comes from knowing the man who killed Don Ly, Leeto's father, a Vietnamese immigrant and hard-working fruit vendor, is still out there.

Ly was stabbed to death at age 68 outside the family home while loading up his food truck at 4:30 a.m. three years ago.

April 18 marks the third anniversary of the murder. For his surviving family members, every day is still a struggle.

"That was his place on the couch," said Nary Ly, 44, Don's daughter, pointing to the corner seat in the family's South Philly home. "Even now, I come in, I still look at the corner. Even though it's empty, I know my dad is here."

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Don Ly brought his family from a rural area of Vietnam to the United States in 1990, in part to help his children get an education, they said, afterward settling in Philadelphia. His children describe him as a generous man and hard worker.

"If it's not true, he not say it. He always honest. He always give," said Leeto, who wrote an essay about his father's life story online after the murder.

"It never occurred to us that something like that can happen," Leeto said. "My dad never did anything bad to anyone in his life. ... Why he deserve this? He should have had a long life."

In the years since Don's murder, the family has put up wanted billboards and even got an honorary Don Ly Place sign hung up on their street.

Don's widow, Saruong Thach, has taken over operating his fruit cart in University City, but it's just to help her cope with the grief, her children said.

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"She just work to pass the days," Nary said. "It's so much for her … Every day she says, 'I'd rather die than live.'"

In a city with hundreds of murders a year and a huge backlog of unsolved cases, the Lys are looking at tough odds. In 2015, the homicide unit reported a 52 percent rate of closing cases.

On the morning of the murder, surveillance cameras nearby caught grainy footage of the suspect calming walking away after he stabbed Ly in what may have been a botched robbery.

"This happen for no reason," Leeto said. "It's just a senseless act."

"We always say we were fortunate that we came to this country. But then in a turn, my dad end this way," Nary said.

The Ly family still clings to a deep belief that their father's killer will be found.

"We need justice. We need closure so we can go forward," Nary said. "I really believe one day a detective will call me and say I got this person for you — and maybe at that time our hearts start to fill up a little."

A $20,000 reward is available for information leading to the arrest of Don Ly's killer. Tipsters can call 215-686-TIPS (8477) or text PPDTIP (773847).