1.   An industry-commissioned study said a broader requirement could cost billions of dollars extra in line testing and installation of emergency cutoff valves.

2.   Some water reservoirs were near overflowing, and engineers were ready to open emergency valves, said BTA.

3.   Some water reservoirs were near overflowing, and engineers opened emergency valves, said BTA.

4.   The accident occurred when emergency valves opened automatically after pressure rose in tanks holding malathion at the plant, Gutierrez said.