That morning, he was sweeping trash near the Rainbow Day Care Center, at 26th and Huntingdon streets, in North Philadelphia, when he discovered a newborn baby, abandoned in a puffed-out, shabby cardboard box.
The baby, whom nurses and social workers call Noel, has been in good condition at St. Christopher's Hospital for Children, as donations pour in and dozens of folks clamor to adopt her.
"It's like being reborn," said Keller, a South Carolina native who worked as a truck driver for more than 50 years.
Before Noel, Keller wasn't one to call his children regularly. He used to touch base with his youngest daughter, Deanne McNair, about once a month.
"Now he calls me every day - maybe a couple of times a day," McNair said yesterday. "One day he called four times. I think it's very sweet. It's like he has a bigger heart since finding the baby."
Her dad calls to ask about her five children, to find out how she's feeling, their plans for the day.
"I'm glad someone found the baby, but I wonder why it was him, my dad, who found the baby," she said. "Maybe it's why he's opening his arms more for his own kids."
Keller can't explain exactly why saving Noel changed him. "I just believe I was there for a reason," he said. "I believe in destiny."
Keller, who works for a church that owns properties near the day-care center, thought at first that the box was full of garbage, so he was hauling it to the trash heap. But he heard whimpering, then faint cries.
He opened the box to find the little blood-streaked girl, her umbilical cord still attached. The baby, who weighed 5 1/2 pounds, was wrapped in a red-and-white houndstooth-patterned blanket, a woman's brown sweater, a black bathrobe with pink polka dots and a large peach-colored bath towel. Keller dialed 9-1-1.
About 50 people have called the Department of Human Services to adopt Baby Noel, said DHS spokeswoman Alicia Taylor.
Baby Noel will be placed with a licensed foster family who wants to adopt her, she said. Because the mother hasn't been found and no family member can be identified, the adoption process will move relatively quickly: Authorities said that the child could be adopted in about a year.
DHS will accept clothes and toys at its first-floor office at 1515 Arch St. through Friday. DHS cannot assure that all donated clothing and toys will go to Noel; some items may go to other needy children, Taylor said.
Meanwhile, Keisha Browning, of the city's Lawncrest section, said last night that she and her friends will have a "baby shower" for Noel on Thursday to show her gratitude for a recent string of good fortune.
Within a couple of weeks, a pastor paid about $150 to Burlington Coat Factory so that Browning could take home a mirror she'd put on layaway. Then she won $250 at a school raffle.
Browning said that she will deliver donated toys and clothing to DHS.
"I just had all this good happen, and then I saw this baby who had just been left like that," she said. "I just knew I had to do something."