Westbound traffic suddenly came to a standstill around 2:30 p.m. Thursday, and a woman sprang from her car, holding a baby, screaming for help.
It was a sight that jarred motorists on the busy Dolphin Expressway.
Pamela Rauseo, 37, of West Kendall, quickly got help for her 5-month-old nephew, little Sebastian de la Cruz, who was turning blue.
Rauseo said she was in a panic, thinking she could not let anything happen to the baby while in her care.
"My sister had trusted me with him," she told reporters.
Drivers stuck in 836 traffic just east of 57th Avenue swung into action.
Lucila Godoy, 34, of Miami left her 3-year-old son in her car to help Rauseo revive the unconscious infant, who she said was born prematurely and had respiratory issues.
Miami Herald photographer Al Diaz, stopped right behind Rauseo, jumped out of his car.
"I heard screaming," he said. He saw a woman pop out of the car in front of him "screaming that the baby can't breathe."
Diaz quickly jogged through traffic lanes to summon more help. He found Sweetwater police officer Amauris Bastidas, who ran to the scene and took over CPR for Godoy, performing chest pumps while Rauseo breathed into the baby's mouth.
"I lifted him up in the air and moved him up and down," Bastidas said. "He started breathing and crying."
Then the baby stopped breathing again.
The trio frantically started CPR again and got the baby breathing. By that time, more help had arrived.
Capt. Anthony Trim and Lt. Alvaro Tonanez with Miami-Dade Fire Rescue's hazardous materials unit — also stuck in traffic — jumped out of their separate cars. They were returning from a meeting and happened to hear the emergency call over the radio.
Trim and Tonanez ran up and found Sebastian breathing — but barely.
"The aunt gave him the baby," Trim said of Tonanez. "He did a quick check and made sure the baby's airway was open."
Miami Fire Rescue arrived moments later and rushed Sebastian to Jackson Memorial Hospital's Pediatrics unit.
The baby was listed in stable condition Thursday evening, a hospital spokeswoman said.