EAST HELENA -- With a resonating ";boom" the iconic smoke stacks that for decades stood as silent watch over East Helena slowly crashed to the ground this morning, shaking the earth and signaling the end of an era.

An estimated 3,000 to 5,000 people scattered among the fields around the former Asarco lead smelter to view the explosion, which went off without a hitch at 7:38 a.m. under cloudy skies.

It was an emotional moment for many.

";As history fell to the ground, I looked around the crowd and saw quite a few tears," Lewis and Clark County Sheriff Leo Dutton said. ";I picked up a piece of the stack ... and will put it on my desk to memorialize this day."

Chester Grace with Dykon Explosive Demolition Corp. was the master blaster, and Kelly Arnold with Cleveland Wrecking Co. pushed the two detonating buttons simultaneously. Afterward, both were giddy with delight at how well the demolition went on the 200-, 400- and 425-foot stacks.

";They moved a little slower than I wanted them to. I was holding my breath," Grace said afterward, wearing a broad smile. ";That 425 reacted totally different than I thought it would. In my opinion, that was the weakest of the three stacks. I thought once we shot the front out it would shift and come down mighty quickly. But it didn't do that. It reacted very slowly.

";I'm glad I was wrong."

Arnold added that the demo was ";awesome, just awesome."

";The weather and the wind were perfect," Arnold said. ";We were a little worried this morning with the thunder and lightning, but it passed and we decided to cut the rebar, then we were committed. We knew it was going to go."

The atmosphere was almost festival-like in many areas, as families laughed and munched on cinnamon rolls while sipping hot drinks, and a soft rain fell in the 56-degree weather.

But all discussions stopped, and all eyes turned toward the smelter as hoses began pumping the first of 90,000 gallons of water into the air, and squad cars broadcasted first a three-minute warning, then a one-minute warning.

Focusing still and video cameras on the stacks, the crowd counted down with Dutton over a loudspeaker until Arnold pushed the buttons. With a collective gasp, people held their breath as the stacks laid down like felled logs.

The smaller, brick stack, built between 1910 and 1920, was first to hit the ground, followed by the 80-year-old concrete 400-footer. The concrete 425-foot tower, erected in 1981, seemed to almost pause in midair before picking up speed, landing on the ground and sending up a plume of white and gray dust.

In less than a minute, it was over.

The crowd cheered, with some shouting out ";Do it again!"

On a hill south of the plant, a group of former smelter workers stayed afterward, eying their former employer with stoic faces. Howie Anderson, who Asarco employed for 20 years, noted that they gathered Thursday night at the VFW post for a ";Blow Your Stack" party.

The group didn't have much to say.

Nearer the stacks, Harry ";Stack" Kovich noted how he put in 44 years at the lead smelter after he graduated from high school in 1936. He was philosophical about the stacks coming down, but noted that Asarco was a good company to work for back in the day.

";They took care of us. I'd make about $3 and some cents per day," Kovich said, adding that he got his nickname while playing for the Smelterites, Asarco's baseball team. ";But what can you expect today? I figured they'd need to clean up the area, so clean it up."

Grace said they drilled 188 holes and used 186 pounds of explosives for the three stacks. The short, brick stack needed the most nitroglycerine-based dynamite because it had the thickest walls.

";That took almost half the dynamite," Grace said.

Jon Nickel, one of the few remaining Asarco employees who is in charge of the plant's demolition, was smiling afterward but said he wiped away a tear as the mighty stacks fell.

";It couldn't have gone better, but there was a little bit of emotion there," he said. ";We just got done walking through the area, and if you took a knife and split (the biggest) stack from top to bottom -- it's laid open like a cracked egg. It's amazing. The other two stacks are demolished. I'm amazed at the amount of rubble."

That rubble is mainly concrete and rebar, which will be pulverized into small pieces and interred in a lined hazardous waste landfill on the south end of the plant, along with the tons of other materials from the dozens of plant buildings that have been demolished during the past three years. Nickel said that work will take a couple of weeks.

Lead smelting operations began in East Helena in 1889, and the American Smelting and Refinery Co., or Asarco, was formed a decade later. High energy costs and low metal prices prompted Grupo Mexico, which bought Asarco in 1999, to ";idle the East Helena smelter plant in 2001. Asarco filed for Chapter 11 bankruptcy protection in 2005.

Legal arguments are currently under way in a Texas federal bankruptcy court as to the purchase of Asarco's assets.

Earlier this week, India's Sterlite Industries offered $1.58 billion cash for Asarco, up from a previous $1.1 billion bid. Including a note to creditors with a value of $83 million, the total value of the bid is $1.67 billion.

Asarco's parent company, Grupo Mexico, also raised its bid this week from $1.55 billion to $2 billion.

It's unknown when Judge Richard Schmidt will make a decision on the bids, weighing what is the best option for Asarco's creditors.

In the eyes of many East Helena residents, the lead smelter permanently closed after the April 2001 shutdown, even though, in order to list the plant as an asset, Asarco has continued to call the closure ";temporary." Iver Johnson, who's overseeing the demolition of structures at the plant for the state Department of Environmental Quality, said he's long considered the closure permanent.

";The state has considered it a closed facility for lead smelting purposes," Johnson said, noting that there's been some interest by outside parties to use the remaining slag pile for a variety of purposes.

Reporter Eve Byron: 447-4076 or eve.byron@helenair.com