Updated

Events May 7, Day 18 of a Gulf of Mexico oil spill that began with an explosion and fire on April 20 on the drilling rig Deepwater Horizon, owned by Transocean Ltd. and leased by BP PLC, which is in charge of cleanup and containment. The blast killed 11 workers. Since then, oil has been pouring into the Gulf from a blown-out undersea well at a rate of about 210,000 gallons per day. The slick threatens the U.S. coastline.

DIVERTING THE FLOW

Underwater robots positioned a giant 100-ton concrete-and-steel box over a blown-out well at the bottom of the Gulf of Mexico on Friday in a first-of-its-kind attempt to stop oil gushing into the sea.

A spokesman for oil giant BP PLC, which is in charge of the cleanup, said the box was suspended about 200 feet above the main leak and was being moved into position, though it could be Saturday before that happens. Several undersea cameras attached to the robots were making sure it was properly aligned before it was lowered all the way to the bottom. The hope is that, perhaps as soon as Sunday, it will funnel up to 85 percent of the oil to a drilling ship.

WHEN WILL IT LAND?

The quest to divert oil spewing from the ocean took on added urgency as it reached several barrier islands off the Louisiana coast, many of them fragile animal habitats. Several birds were spotted diving into the oily, pinkish-brown water, and dead jellyfish washed up on the uninhabited islands. Residents of Louisiana, Mississippi, Alabama and Florida are anxiously waiting to learn when the huge oil slick might come ashore.

WESTERLY SPREAD

Recent satellite images show oil from the spill in the Gulf of Mexico is extending west around the Mississippi Delta. Shots taken by a Canadian satellite Wednesday night reveal the extension looks like a finger reaching out from the main patch. The oil is in streaks ranging from a few feet wide to much larger swaths.

OFFSHORE OIL PORT

The oil spill could force closure of the Louisiana Offshore Oil Port next week, authorities said Friday. The port, known as LOOP, is one of the leading facilities for imported oil, handling up to 1.2 million barrels a day and feeding half the nation's refinery capacity. Tankers too big to enter the Mississippi River pull up and hook into a pipeline system that sends their oil to onshore refineries. Current projections show the oil spill from the Deepwater Horizon disaster could reach the port next week, said Sale Sittig, director of the Louisiana Oil Terminal Authority, an oversight body for LOOP.

BLOWOUT PREVENTERS

Federal regulators say they are going to examine whether the last-resort cutoff valves on offshore oil wells are reliable enough in light of the explosion and massive oil spill in the Gulf of Mexico. Deputy Director Walter Cruickshank of the Minerals Management Service said during an Associated Press interview Friday that his agency had been comfortable that the huge cutoff valves, known as blowout preventers, worked well. That was before BP PLC's Deepwater Horizon rig exploded off Louisiana on April 20 and began spewing at least 210,000 gallons of crude per day after its blowout preventer failed.

REDNECK RIVIERA

It's easy to see why generations of Southerners have flocked to the stretch of northern Gulf Coast affectionately called the "redneck Riviera" — and why they're worried about whether a massive oil spill is about to ruin their down-home playground. Matt Dagen, manager of a beach restaurant and entertainment complex, can't help but look at the emerald green waters and spotless Alabama beach and worry that a lifestyle, not just wildlife and dollars, is in peril.

POSSIBLE HEALTH THREATS

State and federal authorities are preparing to deal with a variety of hazards to human health if and when the full brunt of the toxic mess washes ashore. While waiting to see how bad things will get, public health agencies are monitoring air quality, drinking water supplies and seafood processing plants and advising people to take precautions. Little if any oil has reached land thus far, but shifts in wind speed and direction could propel the slick toward populated areas.

LESSONS LEARNED

Nearly eight years ago to the day, Coast Guard Vice Adm. Thad Allen was a commander, and played the leader's role in a mock oil disaster about 10 miles off the Louisiana Coast. Today, he's in charge of the government's real-life response to what was once the unthinkable and something earlier drills didn't anticipate — a deadly explosion on a BP rig and thousands of barrels of oil a day spewing from a deepwater well. The 2002 exercise offered valuable insights, including how to set up command and response teams, and how to coordinate the response among private and public officials, Allen said. But he and others are haunted by things not learned, not anticipated and not followed from the earlier drill.

SEAFOOD

Federal officials have expanded an area that is off-limits to fishing because of the oil spill in the Gulf of Mexico. The National Oceanic and Atmospheric Administration said Friday an area from the Southwest Pass of the Mississippi River to south of Pensacola, Fla., is now closed. NOAA spokeswoman Christine Patrick said the initial closure was 6,814 square miles and the new area is 10,807 square miles.

Late Thursday, Louisiana officials closed shrimping in state waters from South Pass of the Mississippi to the eastern shore of Four Bayous Pass just east of Grand Isle.

Earlier, state waters east of the Mississippi were closed to seafood harvesting.