Homeland Security to conduct gas tests in NYC Midtown, subways

The simulation, which will use colorless, odorless and harmless "tracer" gases, follows a smaller effort in March that focused on the Madison Square Garden area. This time, a team of more than 150 researchers and volunteers working on the Urban Dispersion Program's second field study will fan out over a much larger section of midtown, ranging from 37th to 59th streets and from 10th to Third avenues, and including stations along the Broadway subway line and other lines in the area.