California Police Deliver Baby Boy in Post Office Parking Lot

— -- California resident Vanessa Prado and her boyfriend Dennis Dillard were driving to the hospital early Thursday morning when suddenly Prado told Dillard to pull over -- and fast.

Prado, 36, who was pregnant with the couple's second child, was about to give birth.

Dillard, 32, parked in the lot of the local post office and quickly dialed 911.

In a matter of minutes, San Diego Police Department officers Matt Enderlin and Eric Hustad arrived at the scene and helped deliver Pierce Dillard, a 6-pound baby boy.

"I don't know what would've happened without the officers' help. They're amazing," Dillard told ABC News. "Matt even drove my car to the hospital so that I could ride [with the] paramedics, Vanessa and my new son."

The new father told ABC News that when 2-year-old Ariah Dillard, the couple's first child, was born, Prado was in labor for about 16 hours.

"My son was very calm the entire morning," Ken Dillard, 69, Dennis Dillard's father said to ABC News. "They [Vanessa & Dennis] left the house no later than 6:15 a.m. and Pierce was born at 6:20 a.m."

According to Dennis Dillard, Prado started having contractions around 4 a.m. but was not overly concerned because the baby wasn't due for another 20 days. By the time Prado and Dillard left their Mira Mesa, California, apartment, the contractions became more frequent.

After the baby was born, Enderlin and Hustad accompanied the couple to Scripps Memorial Hospital La Jolla.

"In the eight years that we've been partners this was one of the most memorable," Enderlin told ABC News, referring to Hustad. "We're just happy that there were no complications, it was definitely a satisfying experience."