1.   A former safety coordinator for Chevron USA has filed a lawsuit claiming he was improperly fired for reporting a release of lethal gas from a company refinery last year.

2.   But only four other states -- Arizona, Maryland, Mississippi and North Carolina -- have continued to use lethal gas.

3.   Clayton said he expected the indictment to contend that the heating system had been installed in such a way that it did not properly vent the lethal gas.

4.   He elected not to choose a means of execution, after the warden told him that lethal gas was a quick and painless way to die.

5.   If combined with acid, it produces a lethal gas.

6.   Indeed, both lakes contain more lethal gas than they did before the eruptions.

7.   Since last year, California law has allowed prisoners facing execution to choose to die by one of two methods -- lethal gas or lethal injection.

8.   The Japanese armed forces were using poison gas in their battles against Chinese troops, and so some of the prisoners were used in developing more lethal gases.

9.   The lethal gas is believed to have been hydrogen cyanide, Mears said, but further testing is needed to confirm that.

10.   The two previous executions in the past seven years were done by lethal gas.