That's breakneck speed for a fire in the middle of the night.
The face of evacuation procedures might be changing as a result of lessons learned from last year's fierce wildfires in California.
Fourteen fires, from Oct. 21 through Nov. 4 last year, killed 24 people, destroyed 3,710 homes, and burned 750,000 acres.
In some smaller communities, evacuation orders were issued via a helicopter equipped with a loudspeaker system, recalled Thomas Cova, a researcher from the University of Utah.
In the future, instead of hearing an mandatory evacuation order, residents may be given the official choice: evacuate or "shelter-in-place."
At least some research has shown that if residents are given the choice between evacuating and sheltering-in-place - that is, staying in their homes or staying in a community shelter - death tolls during wildfires are actually lower. One reason is because, if "we let people sort it out for themselves," they might avoid unplanned, rushed and risky evacuations.
Cova and other fire experts spoke at the 29th Annual Hazards Research and Applications Workshop in Boulder, Colorado.
Evacuations are typically made when a wildfire draws between two and eight miles from homes, said Cova. "But some evacuations during the 2003 wildfires were as far as 10 miles out when they were playing it cautious."
During one of the blazes - the Cedar Fire - the evacuation was frightening for residents because it took place at night. The fire started on Oct. 25 at dusk. It burned 273,000 acres, demolished 2,820 structures, and killed 14 people.
At its peak speed, the Cedar Fire burned 12,000 acres per hour, Cova said, or two to three acres per second. "That's breakneck speed for a fire in the middle of the night."
Cova remembered some harrowing evacuations. "One family warned their neighbors to leave." The blaze was moving so fast the community hadn't received official word, and had to rely on its own judgment. Both families survived, and this is what's known as a "spontaneous evacuation," explained Cova.
Another person survived by jumping into a pool. Three family members died trying to get to a reservoir.
"In Hamilton almost every strategy for saving yourself was used. People were fending for themselves. But nobody who sheltered in place perished. Last-minute or late evacuations are risky. Some people were waiting way too late," said Cova.
Australia has already ceased all mandatory evacuation orders, he said, in favor of giving residents the choice of evacuating or sheltering in place.
And in the U.S., he said, "sheltering in place is likely to be used in lieu of evacuating in an increasing number of cases. This is especially true in communities with defensible structures, or with good shelters."
When there are enough defensible structures, people left in a community not only may avoid injury and death, "they can help put out small fires," that stem off a larger blaze, added David Evans of the National Institute of Standards and Technology.
But for a community that has no shelter - and has homes that are indefensible - sheltering in place might not be an option, he admitted. In the community of Mission Canyon, near Santa Barbara, there are more than 420 homes and only two exits. Back in 1938, when the community was founded, there were six homes - and the same two exits.
Part of planning successful evacuations involves trying to understand the progression of fires, and then planning communities around that knowledge, said Evans.
"Houses are being built in the ring of defensible space," he pointed out.
Predicting a fire's progression is easier when the blaze is burning only forest areas. "Then there are three factors: a bed of fuel to be consumed, a line of fire front, and a bed that has been consumed," said Evans.
When the fire becomes a "wildland urban interface" blaze, modeling its progression is more challenging. In a community fire, the blaze may consume a whole development, he explained, giving the example of a community surrounded by highly flammable eucalyptus trees.
"Historically, we've studied fires in the wildland with two-dimensional modeling but for wildland urban interface fires, you need 3-D effects. Any modeling requires much more detail."
California tends to have major fires about every ten years, said Stephen Sellers of the California Governor's Office of Emergency Services. Emergency managers learned valuable lessons last year and from earlier decades, he said. "We have improved emergency management systems, and we have better land use practices," he said. "We have become more fire resistant. For example, some communities have non-flammable materials for patio covers."
And citizen involvement has become a big plus, he said. "Some groups formed in the 1993 fires were educating citizen-to-citizen about what to expect from FEMA and insurance companies.
"People really matter," he added. "And political leadership makes a difference."
The fire occurred just when former California Gov. Gray Davis was being recalled, and Gov. Arnold Schwarzenegger took office.
"We need the leadership necessary to say we can't do business like this anymore, he said, "because we are going to have more fires," he said, and older houses are more fire vulnerable because they don't have to meet revised fire codes. "We have low humidity, a heavy fuel load, and 60-mph Santa Ana winds. A spark goes off or a crazy arsonist runs around."
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