By Keith Coffman
DENVER, Sept 15 (Reuters) - Colorado officials warned on Sunday the death toll from the week's severe flooding could rise as it was confirmed that a second person was missing and presumed dead, in addition to four deaths previously verified.
The 80-year-old woman had been at home with an injury when the building in which she lived was destroyed, the Larimer County sheriff's office said on its Twitter feed on Sunday.
Previously, authorities had confirmed that a 60-year-old woman was missing and presumed dead after witnesses said they saw her mountain home swept away. Their names have not been released.
Those two are among hundreds who remain unaccounted for, although officials said the bulk of those missing are listed as such because they do not yet have working telephone service.
"We're still bracing. I mean, there are many, many homes that have been destroyed," Colorado Governor John Hickenlooper said in an interview with CNN on Sunday.
Officials have already confirmed four deaths since relentless rainfall began flooding the usually semi-arid region nearly a week ago. President Barack Obama declared the area a federal disaster over the weekend.
Some areas have seen more than a year's worth of rain in just a few days, according to the National Weather Service. The floods have destroyed roads and buildings.
About 500 people were still unaccounted for in two flooded counties and nearly 2,000 have been evacuated from their homes, Hickenlooper said. While many may just be without communication services, officials warned that the death toll could rise.
National Guard troops and local emergency crews were continuing to search for and rescue people trapped by the waters. (Writing by Jonathan Allen; Editing by Scott Malone and Maureen Bavdek)