A 28-year-old pregnant woman died Friday night after apparently falling out of the passenger side of a pickup truck on Kamehameha Highway in Punalu'u, police said yesterday.

The woman was identified as Delphine Haina, of Wai'anae. The condition of her fetus was not released yesterday. An autopsy will be performed tomorrow, an investigator at the city Medical Examiner's Office said. No arrests have been made in connection with the case.

The accident happened about 8:30 p.m. on Friday as the truck was traveling Kahuku-bound at about 35 mph near 53-627 Kamehameha Highway.

Police said Haina and her boyfriend, who was driving the blue Chevrolet truck, were arguing just before her fatal fall from the truck's cab.

Haina was taken to Kahuku Hospital in critical condition and then airlifted to The Queen's Medical Center, where she died.

Witnesses said she landed on an asphalt driveway near the roadway. They also said she was visibly pregnant. Good Samaritans started cardio-pulmonary resuscitation on Haina shortly after the accident, and paramedics took over once they arrived.

Jim Kruger, who lives just up the road from where the accident happened, said he heard a screech of tires just after 8:30 p.m. on Friday. When he looked out to see what had happened, he saw a weeping man holding Haina.

Kruger said the man hugged her to his chest and then started to attempt mouth-to-mouth resuscitation. The man, presumably her boyfriend, appeared to be in his early 20s, Kruger said. He also appeared to be in shock, he said.

Reach Mary Vorsino at mvorsino@honoluluadvertiser.com.