May 23: Louisiana coast's battle against drifting oil expected to last months, if not years. 'Top kill' to stop Gulf of Mexico oil spill may be delayed; Coast Guard admiral expects 'constant activity' by BP. State officials say they won't wait for approval to build sand barriers.
Read more about efforts to stop the oil spill.
May 22: State closes southwestern portion of Barataria Bay to all fishing. Deepwater Horizon oil spill revealed an industry ill-prepared to deal with 'black swan' event.
Read more about oil spill impact of Louisiana Fishing industry.
May 21: Grand Isle closes beaches due to oil on shore.
Read more about the oil spill beach closure.
May 20: BP concedes more oil spilling into Gulf than originally estimated. Feds order BP to put all Gulf oil spill data on Internet. A month after explosion, oil from Gulf of Mexico spill washes ashore in populated areas.
May 19: BP's estimate of volume of Gulf of Mexico oil leak is dramatically low, Purdue expert says. BP may make first attempt to seal Gulf oil well Sunday or Monday. Costly, time-consuming test of cement linings in Deepwater Horizon rig was omitted, spokesman says.
May 18: 19 percent of Gulf fishing shut down because of oil spill. Gulf of Mexico oil spill 'increasingly likely' to enter Loop Current, travel to Florida Keys. Several Louisiana wells shut down as a precautionary measure because of Gulf of Mexico oil spill.
May 17: Insertion tube draining 1,000 barrels per day. 8 investigations underway into Gulf of Mexico rig explosion and oil spill. Tar balls found off Key West, Fla., Coast Guard reports.
May 16: Giant underwater plumes of oil found in Gulf of Mexico. Mile-long tube finally draining oil from busted pipeline in Gulf of Mexico.
May 15:First attempt to stop oil spill with insertion tube has failed, according to U.S. Interior Secretary Ken Salazar. Oily shrimp force new fishing closures Terrebonne Parish; two oyster harvesting areas reopened in St. Bernard Parish.
May 14: Tiniest victims of the Gulf of Mexico oil spill may turn out to be most important. Insertion-tube strategy for containing Gulf of Mexico oil spill to be tried tonight.
May 13: BP says its Gulf of Mexico oil spill costs now at $450 million. Louisiana using Mississippi River diversions in Gulf oil spill battle. Oil at 2nd barrier island off Terrebonne Parish. Offshore drilling supported despite Gulf of Mexico oil leak, poll suggests. Insertion tube strategy chosen to address Gulf of Mexico oil leak.
May 12: Tar balls reported at South Pass in Plaquemines Parish. Oil on shore of barrier island off Terrebonne Parish, state reports. BP still deciding how best to deploy 'top hat' to contain Gulf of Mexico oil spill. Criminal charges likely in Gulf oil spill, newspaper group reports.
May 11: Gulf of Mexico oil leak hearings in Senate leave major questions unanswered. Smaller 'top hat' containment box being lowered over Gulf oil leak.
May 10: BP prepares second, smaller containment dome, and for "kill shot" on leaking oil well in Gulf of Mexico. BP president to face congressional questioning in Gulf of Mexico oil spill. Gas surge shut well a couple of weeks before Gulf oil spill.
May 9: After Saturday's containment box failure, BP may try again with a smaller version.
May 8: Gulf of Mexico oil leak response hampered by frozen crystals clogging containment box.
May 7: Coast Guard confirms report of Gulf oil spill reaching Chandeleur Islands. How the Gulf of Mexico oil spill happened: a graphic presentation. Booms being deployed to protect Rigolets, Chef Menteur passes from oil spill. Containment box to stifle oil spill in Gulf has been placed over spewing well.
May 6: 2 dead birds found near islands off Plaquemines Parish. BP did five "controlled burns" Wednesday of oil released in Gulf of Mexico oil spill. BP offers spill cleanup class to St. Charles commercial fishers. Oil fumes delaying lowering of containment box over Gulf oil leak. Safety fluid was removed before oil rig exploded in Gulf.
May 5: BP caps one of three Gulf of Mexico oil leaks but the flow is undiminished. Containment box meant to stifle Gulf of Mexico oil spill is en route to accident site. State, Corps consider opening Bonnet Carre Spillway to keep Gulf oil spill at bay. Louisiana seafood proclaimed safe amid Gulf oil spill fears.
May 4: Gulf oil spill will not cause cash flow problems for state, Jindal says. Jindal mobilizes another 500 troops for Gulf of Mexico oil spill. Rig workers sue in Gulf oil spill, saying they were in lifeboats for 10 hours after explosion. BP CEO Tony Hayward says spending on Gulf oil spill unlikely to be limited by cap. BP attaches shut-off valve, will begin shipping containment structures for Gulf of Mexico oil spill.
May 3: Chemicals at source reducing amount of oil spill reaching surface of Gulf, BP CEO Tony Hayward says. A board investigating what caused the explosion and spill plans to hold its first public hearing in about two weeks. BP CEO Tony Hayward said that BP was not responsible for the accident, but will pay for the cleanup. Jindal says state and parish plans moving forward to contain oil spill. Containment boxes are being built to capture oil spilling into Gulf.
May 2: President Barack Obama travels to Gulf for update, assures Louisiana that oil spill has federal government's full attention. Oil rig explosion and spill in Gulf of Mexico was because of failed equipment, according to BP Chairman Lamar McKay. St. Bernard Parish fishers hit the coastline to fight spreading oil from Gulf spill. Offshore fishing in Gulf of Mexico oil spill area closes.
May 1: St. Bernard Parish fishers begin training to assist in fight against Gulf of Mexico oil spill. Booms readied near Chef Menteur, Ft. Pike, to protect Lake Pontchartrain from Gulf of Mexico oil spill. The Obama administration names Adm. Thad Allen, the retiring U.S. Coast Guard commandant who directed recovery operations during Hurricanes Katrina and Rita, to direct Gulf of Mexico oil spill response. No signs of oil at mouth of Mississippi River or Gulf Outlet yet as strong winds stall work deploying booms.
April 30: The Louisiana National Guard prepares to send communication equipment, boats, all-terrain vehicles and other equipment to help combat the oil spill. First bird covered in oil is caught and cared for.
April 29: An oil spill protection meeting draws nearly 200 fishers to Chalmette. Governor Bobby Jindal issues emergency declaration in oil leak in Gulf of Mexico.
April 28: Crews begin controlled burn of oil. This method is used to limit the amount of oil that could wash ashore. The NOAA announces that five times as much oil (210,000 gallons) is spewing in the Gulf of Mexico than originally thought. A new leak is discovered, as well, bringing the total to three.
April 25: Robot subs are used to try to stop the leak, which continues at a rate of about 42,000 gallons per day.
April 24: Contrary to what the U.S. Coast Guard said the previous day, oil is leaking from the undersea well at the Deepwater Horizon site at a rate of about 1,000 barrels per day, or 42,000 gallons.
April 23: The U.S. Coast Guard says no oil is leaking from the undersea well at the Deepwater Horizon site. The U.S. Coast Guard suspends the search for the 11 missing workers.
April 22: About 100 survivors from the explosion arrive on shore. The 11 workers unaccounted for are still missing. Deepwater Horizon sinks into the Gulf of Mexico.
April 21: The U.S. Coast Guard holds a news conference to discuss the explosion and those missing. "We have no idea where the 11 unaccounted-for personnel are," said Mary Landry, commander of the Coast Guard's 8th district headquarters.
April 20: The Deepwater Horizon deep-water oil drilling rig explodes and catches fire in the Gulf of Mexico. 126 people were on board, 11 dead and at least 17 are injured.