Employees of British Petroleum, Halliburton and Transocean testified before the Senate Environment and Public Works Committee on Tuesday about a BP off shore drilling rig in the Gulf of Mexico that exploded April 20th. The explosion took the life of 11 BP employees and has created the largest oil leak in US history. Here Lamar McKay Chairman and President BP America; Steven L. Newman President and CEO Transocean Ltd.; Tim Probert Chief Health, Safety and Environmental Officer, Halliburton.