Powerful Texas blast left nearly 100-foot-wide crater

Walls warped or blown off entirely, even ones made of brick. Roofs sunken in, if they are still visible at all. Garage doors lying in yards.

And, at the center of it all, a crater nearly 100 feet wide and 10 feet deep.

On Tuesday, the devastation from last week's explosions at a West, Texas, fertilizer distributor became more eerily apparent as officials offered new details and opened more roads around the town's hardest hit areas.

While the blast's lethal power was clear, many other questions remain.

Why did a fire start in the facility, which had shut down to workers for the day? How did that fire spark the massive explosion that tore through the northern part of town -- killing 14 people, including nine first responders, and injuring hundreds of others? What, if anything, could have been done to prevent the tragedy?

So far, investigators have eliminated the possibility that natural causes started the fire, but they haven't gone beyond that.

When not funneling in and out of the command center at West High School, federal, state and local officials spent Tuesday outside using shovels to methodically search for clues.

Assistant State Fire Marshal Kelly Kistner said investigators were starting in the least-damaged areas, hoping to determine the heat source or material that ignited the fire.

The West Fertilizer Company said its officials are focused on "fact finding," not lawsuits that may come after the blast.

"We continue to do everything we can to understand what happened to ensure nothing like this ever happens again in any community," the company said.

Residents of this tight-knit town of 2,800, meanwhile, tried to get back to normal, though the explosion is never far from their minds.

At the Pizza House on Oak Street, waitstaff and locals discussed the state of their homes while drinking their beers, trying to figure out how to deal with the fact their once quaint farming town now resembled a war zone.

Several hundred residents gathered Tuesday night at a Knights of Columbus hall, some of them standing because the place was so packed, hoping to get answers from officials.

They kept their tempers in check, though it was apparent many residents just want to go home.

Some who live in damaged residences in areas that have been opened up to traffic have gotten that chance.

On Tuesday -- two days before President Barack Obama and first lady Michelle Obama head to Waco, about 18 miles south, for a memorial service at Baylor University -- some of them stood motionless on their front lawns, taking in the devastation.

Others kept busy sifting through what remained or trying to fix what they could. The sounds -- of trailers full of debris rolling by, or the buzz of power tools -- were reminders that, for some, life was moving on.