Carbon dioxide was described in the video as an invisible and suffocating gas.

'The whole square was filled with thick, suffocating gas,' the Soviet journalists said.

It was covered by a thick layer of suffocating gas, killing everyone who dared to enter this area.

He planned to use "suffocating gases" and other chemicals, and tried to recruit others to help him, police said.

This cave was used for religious purposes by priests of Cybele, who found ways to appear immune to the suffocating gas.

They opened their locked doors, spilled out into the cold winter night, wheezing, coughing' In spite of the blinding, suffocating gas, the driver had drawn his revolver.

A fire boss is a person employed at a mine or state certified official, responsible for examining a mine for dangers, particularly explosive, poisonous or suffocating gases.

They said 400 people had been killed in Karbala when Iraqi tanks from the Republican Guard stormed the city, in an attack that also included the use of napalm and what was described as "suffocating gas."

Suffocating gases, as well as carboxylic acid, were emitted from a vent along the Manadas ridge and thick greenish vaporous clouds (of chloric and sulfuric acids) rapidly spread to the plants.

The Davy lamp could also detect high levels of blackdamp (which collect near the floor) by burning less brightly, while methane, another suffocating gas and explosion risk would make the lamp burn more brightly).

He sees this and other drains on the diversity of life as a warning akin to the dying of the canaries miners used to take into the pits; canaries succumb to deadly chokedamp, a suffocating gas found in mines, before human beings even notice the danger.

These suffocating gases, which were probably carboxylic acid, were harmful to the population; the thick water-vapor, which condensed in a reddish color, rapidly spread unnoticed through the local vegetation (a mix chloric and sulfuric acids) which were expelled as aqueous vapors.

The Iranian radio said today that as many as 16,000 people had been killed near the holy cities of Karbala and Najaf, south of Baghdad, when Government troops used napalm, artillery, tanks and what was described as "suffocating gas" against rebels and fleeing civilians.

The Iranian press agency quoted the head of the Iranian delegation of pilgrims, Hojatolislam Mahdi Kharoubi, as saying the police had attacked the Iranians with automatic weapons, used suffocating gases on the pilgrims and fired shots at ambulances carrying away the dead and wounded.

In a report reminiscent of an earlier account of a family of seven, Kwon claims to have watched one family of two parents, a son and a daughter die from suffocating gas, with the parents trying to save the children using mouth-to-mouth resuscitation for as long as they had the strength.