PORT FOURCHON, La. -- As submersible robots made another risky attempt to control the underwater Gulf oil gusher, the crude on the surface spread, closing in on Florida. BP's stock plummeted and took much of the market down with it, and the federal government announced criminal and civil investigations into the spill.
The stakes couldn't be higher.
After six weeks of failures to block the well or divert the oil, the latest mission involved using a set of tools akin to an oversized deli slicer and garden shears to break away the broken riser pipe so engineers can then position a cap over the well's opening.
But it's a big gamble: Even if it succeeds, it will temporarily increase the flow of an already massive leak by 20 percent -- at least 100,000 gallons more a day. That's on top of the estimated 500,000 to 1 million gallons gushing out already.
In Florida, officials confirmed an oil sheen about nine miles from the famous white sands of Pensacola beach. Crews shored up miles of boom and prepared for the mess to make landfall as early as Wednesday.
"It's inevitable that we will see it on the beaches," said Keith Wilkins, deputy chief of neighborhood and community services for Escambia County.
Florida would be the fourth state hit. Crude has already been reported along barrier islands in Alabama and Mississippi, and it has impacted some 125 miles of Louisiana coastline.
More federal fishing waters were closed, too, another setback for one of the region's most important industries. More than one-third of federal waters were off-limits for fishing, along with hundreds of square miles of state waters.
Fisherman Hong Le, who came to the U.S. from Vietnam, had rebuilt his home and business after Hurricane Katrina wiped him out. Now he's facing a similiar situation.
"I'm going to be bankrupt very soon," Le, 53, said as he attended a meeting for fishermen hoping for help. "Everything is financed, how can I pay? No fishing, no welding. I weld on commercial fishing boats and they aren't going out now, so nothing breaks."
Le, like other of the fishermen, received $5,000 from BP PLC, but it was quickly gone.
"I call that 'Shut your mouth money,"' said Murray Volk, 46, of Empire, who's been fishing for nearly 30 years. "That won't pay the insurance on my boat and house. They say there'll be more later, but do you think the electric company will wait for that?"
BP may have bigger problems, though.
Attorney General Eric Holder, who visited the Gulf on Tuesday to survey the fragile coastline and meet with state and federal prosecutors, would not say who might be targeted in the probes into the largest oil spill in U.S. history.
"We will closely examine the actions of those involved in the spill. If we find evidence of illegal behavior, we will be extremely forceful in our response," Holder said in New Orleans.
The federal government also ramped up its response to the spill with President Barack Obama ordering the co-chairmen of an independent commission investigating the spill to thoroughly examine the disaster, "to follow the facts wherever they lead, without fear or favor."
The president said that if laws are insufficient, they'll be changed. He said that if government oversight wasn't tough enough, that will change, too.
BP's stock nose-dived on Tuesday, losing nearly 15 percent of its value on the first trading day since the previous best option -- the so-called top kill -- failed and was aborted at the government's direction. It dipped steeply with Holder's late-afternoon announcement, which also sent other energy stocks tumbling, ultimately causing the Dow Jones industrial average to tumble 112.
If BP's new effort to contain the leak fails, the procedure will have made the biggest oil spill in U.S. history even worse.
"It is an engineer's nightmare," said Ed Overton, a Louisiana State University professor of environmental sciences. "They're trying to fit a 21-inch cap over a 20-inch pipe a mile away. That's just horrendously hard to do. It's not like you and I standing on the ground pushing -- they're using little robots to do this."
Since the Deepwater Horizon rig exploded on April 20, eventually collapsing into the Gulf of Mexico, an estimated 20 million to 40 million gallons of oil has spewed, eclipsing the 11 million that leaked from the Exxon Valdez disaster.
BP PLC's Doug Suttles said that although there's no guarantee the company's latest cut-and-cap effort to close off the leak will work, he remained hopeful, but wouldn't guarantee success.
Engineers have put underwater robots and equipment in place this week after a bold attempt to plug the well by force-feeding it heavy mud and cement -- called a "top kill" -- was aborted over the weekend. Crews pumped thousands of gallons of the mud into the well but were unable to overcome the pressure of the oil.
The company said if the small dome is successful it could capture and siphon a majority of the gushing oil to the surface. But the cut and cap will not halt the oil flow, just capture some of it and funnel it to vessels waiting at the surface.
The British oil giant has tried and failed repeatedly to halt the flow of the oil, and this attempt like others has never been tried before a mile beneath the ocean. Experts warned it could be even riskier than the others because slicing open the 20-inch riser could unleash more oil if there was a kink in the pipe that restricted some of the flow.
Eric Smith, an associate director of the Tulane Energy Institute, likened the procedure to trying to place a tiny cap on a fire hydrant that's blowing straight up.
"Will they have enough weight to overcome the force of the flow?" he said. "It could create a lot of turbulence, but I do think they'll have enough weight."
But BP's best chance to actually plug the leak rests with a pair of relief wells but those won't likely be completed until August.
The company has carefully prepared the next phase, knowing that another failure could mean millions more gallons spew into the ocean and lead to even more public pressure. And they say they have learned valuable lessons from the failure of a bigger version of the containment cap last month that was clogged with icelike slush.