US probe into DuPont plant deaths

The US Chemical Safety Board is investigating an accident at DuPont's LaPort production facility near Houston, Texas in which four workers were killed and a fifth was hospitalised. DuPont says that there was a release of methyl mercaptan, which is used as an intermediate in pesticide production and for other industrial purposes. Several employees were responding to a leak in a valve, the company notes. It is conducting its own investigation of the incident and co-operating with local, state and federal authorities, DuPont points out.