BP began work on its controversial the Chukchi Sea project Monday . An ice floe forced the company to halt work on Sunday . Shell says it can safely drill off Louisiana 's coast . Environmental groups say a spill there would be catastrophic .
Shell began work on its controversial Arctic project Sunday . An ice floe forced the company to halt work on Monday . Shell says it can safely drill off Alaska 's coast . Environmental groups say a spill there would be catastrophic .