A police investigation into Sunday's crash that killed a woman waiting at a Pawa'a bus stop is focused on what caused a taxi driver to lose consciousness before his 2001 Dodge Caravan veered off the roadway.

It was not known yesterday whether the 52-year-old Honolulu man fell asleep, suffered a medical condition or if drugs or alcohol were factors, but the taxi's passenger, a 45-year-old man from Australia, told police the driver lost consciousness shortly before the 4:50 p.m. crash on Kalakaua Avenue, 80 feet north of Makaloa Street, said lead vehicular homicide investigator Sgt. John Agno.

Excessive speed was not a factor, Agno said.

The minivan crashed into the bus stop and hit a 73-year-old woman. She died at The Queen's Medical Center shortly after 8 p.m.

She was the only person injured out of the six or seven people at the bus stop.

Mark Scott, a journalist visiting from New Zealand, did not witness the incident but was among those who tried to help the injured woman before paramedics arrived.

"She had a terrible injury to her leg but was lucid and talking," said Scott, who was shocked and saddened by news that the woman died.

"It shows you how fragile life is," Scott said. "You're sitting at a bus stop and the last thing you expect. ... " He didn't finish the sentence.

The woman, whose name was not being released by the medical examiner's until her identity is confirmed, died of multiple blunt force injuries from a motor vehicle collision, according to autopsy findings.

"It was a rare situation, unfortunate and tragic," Agno said.

The case for now is listed as O'ahu's second traffic fatality of 2007.

However, an autopsy determined that Harry Kozuma, 73, who was involved in a crash Friday at Lukini Street and Jack Lane in Nu'uanu Valley, died of natural causes — a ruptured abdominal aortic aneurysm — and police are expected to remove that case from its list of traffic fatalities.

Reach Rod Ohira at rohira@honoluluadvertiser.com.