* BP adds another 48 hours to know top kill outcome
* Obama says no "silver bullet" solution to spill
* BP estimates cost of oil spill at $930 million
* BP shares down around 5 percent
(Updates with CEO comment, fishing ban, details)
By Patricia Zengerle and Tom Bergin
GRAND ISLE/HOUMA, La., May 28 BP said on Friday
it may need two more days to know if its complex maneuver to
plug a gushing Gulf of Mexico oil well has worked, while
President Barack Obama warned there was no "silver bullet"
solution to the biggest oil spill in U.S. history.
Trying to assert leadership in the face of growing
criticism over his handling of the spill, Obama toured the
Louisiana Gulf coast, where oil has seeped into delicate
marshlands and shut down much of the lucrative fishing trade.
BP (BP.L) CEO Tony Hayward flew over the Gulf to where his
crew and robots worked on the "top kill" -- the injection of
heavy fluids, materials and ultimately cement to seal the well
one mile (1.6 km) below the surface.
Hayward said the procedure was making progress choking off
the five-week-old leak that has already spewed millions of
gallons (liters) of oil into the Gulf.
"We have wrestled it to the ground but we haven't put a
bullet in its head yet," Hayward told Reuters as he headed by
helicopter to the spill site in the Gulf.
When the top kill began on Wednesday, BP said it would need
up to 48 hours to gauge its success. But Hayward extended the
timeline another 24-48 hours on Friday. [ID:nN28200489]
He said the top kill's chance of success remained at 60 to
70 percent, although experts put the odds at 50 percent.
BP has called the effort to plug the hole "a "rollercoaster
ride," and investors might say the same. BP shares lost 5
percent on Friday, erasing gains made on hopes for a successful
TAKE A LOOK on the spill [ID:nSPILL]
INSIDER TV: link.reuters.com/wuw64k
On his second visit to the Gulf in the five-week crisis,
Obama faced his own steep challenge to convince Americans that
he was in command as frustrated Gulf Coast residents loudly
criticized federal authorities for being slow to act and
offering too little assistance.
"You will not be abandoned. You will not be left behind. We
are on your side and we will see this through," Obama said in a
televised statement after meeting local and state officials and
inspecting the oil spill damage to the coastline.
"I am the president and the buck stops with me," he said.
BP 'WORKING FOR THE GOVERNMENT'
The buck may stop with Obama, but the key to stopping the
environmental catastrophe lies with BP because the federal
government has few tools to work at those depths.
Obama and Hayward have had no contact over the April 20 rig
explosion that killed 11 workers and unleashed the gusher, a
White House spokesman said. But Hayward made clear that the
government is in charge these days.
"We are working for the government," said Hayward. "The
government is running it."
BP views the top kill procedure as its best hope of
plugging the well and containing a spill that has tarred its
reputation and seen some 25 percent, around $50 billion, wiped
off its share price.
The company said on Friday the cost of the disaster so far
was $930 million. That figure is sure to multiply with cleanup
of the oily mess, which is now larger than the spill from the
Exxon Valdez disaster off the Alaskan coast in 1989.
As Hayward flew toward the disaster area, the sheen of oil
and brown patches of crude and dispersant were visible below
some 9 miles (15 km) offshore.
Some 50-60 vessels are in the area working on the BP
containment and the shut-off as 12,000 barrels (504,000
gallons/1.9 million liters) to 19,000 barrels (798,000
gallons/3.0 million liters) of oil escape the well per day,
according to government estimates.
BP began the top kill operation on Wednesday afternoon and
then stopped pumping mud overnight to analyze pressure
readings. It did not publicize the halt for many hours, drawing
fresh accusations it was concealing information from the
public. It denied the charges and blamed an oversight.
"I am angry and frustrated I want this thing stopped as
fast as I can, as we can," said Hayward, adding, "the reality
is that's it's a very challenging technological challenge."
If the top kill fails, BP says it will try other remedies,
such as a second attempt at containing the oil so it can be
transported by pipe to a ship at the water's surface or placing
a new blowout preventer atop the failed one.
FEW LIKE GOVERNMENT RESPONSE
Obama said a team of government scientists was exploring
contingency plans in case the top kill option failed.
"There are not going to be silver bullets or a lot of
perfect answers for some of the challenges that we face," he
said. "This is a man-made catastrophe that is still evolving."
Joe Williams, 53, a charter fisherman in Venice, Louisiana,
watched Obama on television at the local marina and said he
liked it when Obama said "the buck stops" with him.
"If he takes control of it now, that is great because
everyone has been passing the buck," he said.
But Friday brought more bad news for the fishermen. The
National Oceanic and Atmospheric Administration said it was
extending the closed fishing area to about 25 percent of the
federal Gulf waters from around 19 percent before.
Obama inspected oil-trapping booms on a beach and picked up
tar balls, but had little contact with the area's residents in
the five-hour visit.
His tour comes a day after he vowed to "get this fixed."
His predecessor, George W. Bush, was slammed for his
administration's handling of Hurricane Katrina and Obama is
anxious to avoid comparisons.
The spill could turn into a major political liability for
Obama before November elections that are widely expected to
erode his Democratic Party's control of the U.S. Congress.
Public approval of the administration's handling of the
spill has plummeted, according to the latest Zogby Interactive
poll, which surveyed 2,085 people between May 25-27.
Just 16 percent of people surveyed rated the federal
government's response as excellent or good, down from 29
percent two weeks ago.
(Additional reporting by Ed Stoddard in Venice, Louisiana,
Kristen Hays, Erwin Seba and Chris Baltimore in Houston, Jeremy
Pelofsky in Washington, and Pascal Fletcher and Jane Sutton in
Miami; Writing by Mary Milliken, Editing by Sandra Maler)