gas works employee in the blast zone. the cause is still under investigation. classes are back in session at gardena high school a day after two students were found -- were wounded in an apparently accidental shooting. a boy shot through the neck is expected to be fine but a 15-year-old girl who was struck in the head by the same bullet, well, she's in critical condition. los angeles police say the student who brought the gun to school faces charges of assault with a deadly weapon. and the mine safety and health administration says it's honing in on the causes of last year's explosion at a west virginia mine. 29 men were killed in massey energy's upper big branch coal mine. at a briefing for their families last night, they laid out their working theory. it involves a domino effect of natural causes and potential negligence. the agency cautions, though, its final report isn't due for another few months. take a look again at this room. we're still waiting. you are looking at live pictures