By Jillian Beck and Philip Jankowski

As firefighters began making progress on the Hidden Pines fire Thursday, surveys of the destruction revealed that at least 34 homes and structures had been destroyed by the Bastrop County wildfire.

Even as the fire expanded to 4,383 acres -- more than double its size since late Wednesday -- after a sharp shift in wind blind-sided firefighters, weather conditions turned favorable Thursday with calmer winds and higher humidity. But firefighters still only had the fire 25 percent contained as of press time, and they expected it to continue to grow.

Thursday evening, Precinct 2 Commissioner Clara Beckett urged calm as she read a list of the destroyed structures to a crowd of residents gathered in a gym at the Smithville Recreation Center, where many slept on cots the previous night. About 75 residents had gathered there with questions about when they could return to their homes.

"This fire event is not over; it's not even near over," Bastrop County Judge Paul Pape told the crowd. "If you're a praying person, I ask you to pray."

Pape said he expects the number of destroyed structures to grow. County officials wouldn't confirm any structure had been destroyed until making visual confirmation.

Late Thursday, some residents along Kellar and Powell roads were told that they could return to their homes.

As the fire raged for a third day, Gov. Greg Abbott surveyed the damage, issuing a disaster declaration for Bastrop County and announcing that the Federal Emergency Management Agency will reimburse up to 75 percent of costs spent fighting the fire through a grant.

"We grieve for the families and the homeowners who were displaced by this," Abbott said. "This has to be an echo of a nightmare they faced just a few years ago" in the devastating 2011 Bastrop County wildfire.

State resources also began arriving Thursday. Two Black Hawk and two Chinook helicopters began dropping water in the morning. Also on the way are 24 federal emergency managers, eight bulldozers from Florida, four bulldozers from Georgia and three Texas firefighting teams with fire engines.

"This fire has national attention now," Texas Emergency Management Assistant Director Nim Kidd said.

On Thursday, the Texas A&M Forest Service, the state's firefighting agency, called in a DC-10 jet known as the "Very Large Air Tanker,"which is capable of dropping 12,000 gallons of water during each pass over the fire.

It's expected to arrive Friday morning.

The fire burned 650 acres of Buescher State Park and moved into parts of Bastrop State Park on Thursday. The blaze's cause has yet to be determined.

The potential for the Hidden Pines fire to continue to grow is high, according to the Forest Service. Even as it has moved northwest from Buescher State Park into the burn scar of the 2011 Labor Day fire that charred more than 34,000 acres, a fire expert said a lack of tree canopy won't prevent the fire from spreading.

"If it can get into grass, it can advance," said Gordon Wells, a program manager with Center for Space Research at the University of Texas. "It's not necessary for there to be a wind storm."

It was a confluence of events that led to the rapid expansion of the Hidden Pines fire. Soaking rains in May and June allowed vegetation to grow more than usual. Then as areas of Texas began slipping back into drought, those plants, which firefighters refer to as "fuel," dried rapidly. When humidity percentages dipped into the teens, the fire risk escalated, Wells said.

"It only takes a spark for things to advance rapidly," he said.

The good news is that the level of humidity rose into the 20s Thursday. That's still dry, but better, Wells said.

The wildfire risk remains elevated, according to the National Weather Service. Temperatures might approach record levels Friday and are expected to top out in the lower to mid-90s, meteorologist Larry Hopper said.

Winds between 5 to 10 mph will shift from out of the southeast to blow out of the northeast and could push the fire back south.

Outside the emergency shelter at the Smithville Recreation Center, just after residents were told Thursday of the destroyed homes, 50 people gathered at a gazebo at the end of Main Street. Together, they bowed their heads and sang "Amazing Grace."

Local pastors led the group in prayers for the firefighters battling the blaze and prayers for those who have lost their homes. Some people sat on benches, wiping away tears.

"I certainly at this moment in time cannot imagine what those who lost their homes are going through," said Karen Boehk, a pastor with the First United Methodist Church of Smithville. "I just pray in the midst of losing stuff, they can celebrate their lives."

(c)2015 Austin American-Statesman, Texas