Welcome back. BP is in for some tough questioningTuesday as its executives go before a congressional committee looking into the safety of offshore oil drilling. The oil spill caused by an explosion at BP's Deepwater Horizon oil platform is one of the worst in history. Efforts to contain it with a giant dome have failed, and the company now says it will make a second attempt this week with a smaller version dubbed the "top hat". meanwhile the massive slick threatens long lasting damage to the environment and the economy. Coastal communities depend on shrimp and oyster fishing, and on tourism -- all of which could suffer for years.