"We ate pancakes in the morning, and then I started feeling those fake contractions," said Lopez, who was pregnant.
But when the contractions got real, Lopez, her husband and son tried to make it to the hospital.
"I started feeling like this enormous pressure and I was like, 'OK, I am not going to make it anymore,' " Lopez said.
"So, I'm like, 'Crap! What do I do?" and she told me, 'Call 911,'" Alan Lopez, Liliana's husband, said.
Then they waited and prayed. That's when California Highway Patrol officers Kyle Biedermann and Richard Yebra of the Central Los Angeles Area station stepped in.
Get this -- it was Yebra's last day of training.
"You sign up for this job to help others and serve the public and it didn't take long for me in Los Angeles and on the department to actually experience something so joyful," Yebra said.
"We happened to be at the right place at the right time," Biedermann said.
The baby deliver on the 5 Freeway was captured on the officers' dashcam.
At a news conference held Friday, baby Mia was gifted a pink onesie as an official new CHP recruit.
"I was just like, grateful for them to be there," Lopez said. "Until the day, you know, I'm not here, I'll always be grateful."