A 79-year-old woman who stood in line more than five hours for a flu shot (search) collapsed and died after striking her head.

Marie Franklin and her husband, Robert, had been standing with hundreds of other seniors outside a Safeway supermarket on Wednesday when she became pale and weak. She collapsed as she walked toward shade.

Franklin, an award-winning local artist, died from those injuries Thursday. The Contra Costa County coroner's office ruled the death an accident.

"We see it as a fluke accident and choose not to blame anyone," said the Franklins' daughter, Ginni Poulos of Portland, Ore., who flew to her parents' home in the San Francisco Bay area city of Orinda. "We do think it could have been better organized. People wouldn't have had to wait so long if they had more workers or created a better system."

The nation's limited supply of flu vaccine has led to long lines at offices and stores offering vaccinations. Most of those waiting in line are the elderly and young children, those most susceptible to influenza.

The Franklins arrived at the Safeway at 8 a.m. and found hundreds of people already in line. At 1:15 p.m., Franklin got out of line to wait in the shade, leaving her husband to hold their spot.

"She was standing the entire time, with nowhere to sit and no shade," Poulos said.

Teena Massingill, Safeway public affairs manager, said employees brought out chairs, snacks and water for people waiting in line. Many had lined up well before the shots began at 10 a.m. and employees handed out numbers in the early afternoon, sending people home who were not going to be able to get one of the 500 shots available.

"It wasn't a drastic number of people who were told they couldn't be seen," Massingill said. "We're trying to provide these vaccines in the best way that we possibly can."

Police in Concord, another East Bay city, reported that two other seniors, women ages 76 and 83, were hospitalized Thursday after collapsing outside a Costco store from possible heat exhaustion while waiting in a long line for the vaccine.

The government has urged healthy adults to skip the shots after British regulators shut down shipments of vaccine that accounted for nearly half the nation's supply after some batches were contaminated with bacteria.