Lambo was taking her dog Barney for a walk when she was hit.
She was pronounced dead at the scene. Her dog was also killed.
Lambo's walker was caught on the front bumper of the vehicle and was dragged about 200 yards.
Neighbor Albert Perez was the first to find Lambo, as the driver who hit her sped away.
"It was a moment of anger because I knew this had happened, and nobody else was around," he said.
"It's just so sad, like, you still have that gut feeling, like oh my god, you've just seen somebody just lying on the floor," said Dolores Morales, who also witnessed the incident.
"We got out to see if we could help, but I think by then, I think she had already passed on," said Morales. "I don't know if she died on impact, but it was just an ugly scene. It was just horrible."
Lambo was the widow of former Montebello City Clerk Andrew Lambo. Their children said the couple was known for their generosity, especially during the holidays.
"She was just the best lady ever, went to church Wednesdays and Sundays, and literally fed orphans, helped people," said the victim's daughter Jinx Gould.
"She just led a very special life and she was a public servant; her and my dad were both public servants. And she was a wonderful lady," Gould added.
"She was a generous wonderful woman, and I just want justice to be served," said the victim's son Andy Lambo.
The news of Lambo's death is still hard to believe for her neighbor Mike Egurrola, who has known her for 20 years.
"She was a very kindhearted person. She was a church-going person, volunteered a lot of time at the church. We lost an icon in this city," Egurrola said.
Montebello police are searching for the driver of the vehicle and a male passenger. After Lambo was hit, authorities say the passenger got out and pried her walker from the front of the car, showing that the two men knew that they had hit someone.
The driver is described as Latino, 35 to 40 years old, with brown eyes, short and straight black hair, a mustache and goatee.
The vehicle is described as a white two-door 1998 - 2002 model Chevy Silverado with a two-door extended cab, tinted black windows and chrome rims. The truck should have damage to the front chrome bumper toward the right side as a result of the impact.
Anyone with information is urged to call the Montebello Police Department at (323) 887-1313.