SNOPES: An eruption of carbon dioxide from a lake killed hundreds of people.

[Banjo]

Claim: * An eruption of carbon dioxide from a lake killed hundreds of people.

Status: * True.

Origins: * Carbon

dioxide is a substance we generally associate with the happy little bubbles that enliven our favorite brands of soda and beer. We are not accustomed to thinking of it as dangerous, as most of our interactions with it are innocuous. Moreover, memories of high school biology remind us that while we breathe in oxygen and exhale carbon dioxide, plants operate in the opposite fashion by soaking up carbon dioxide and exuding oxygen, making for an efficient symbiotic relationship between people and plants. Carbon dioxide is a natural part of the world around us, ergo, we don't view it with the same level of apprehension with which we regard manmade compounds.

On the fateful night of 21 August 1986, the deep waters of the lake reached their carbon dioxide saturation point, and without warning the lake "turned over," its bottom layer shooting to the surface in a violent, frothy eruption of carbonated water that flew some 250 feet into the sky. The lake waters turned red as dissolved iron was sucked up to the surface by the turmoil.

An estimated 100 million cubic metres of gas emerged from the lake in that explosion, quickly sweeping over the valleys surrounding Lake Nyos and, being denser than air, sinking to suffocate and poison the inhabitants below.

Death came quickly. One man living just two hours on foot from the lake said, "We heard a noise, just like a gunshot." He immediately checked on his two young daughters, and found them already dead in their beds.

A total of 1,746 people were smothered in the night, according to the official casualty toll. The deadly cloud covered an area of up to 12 miles around the lake, killing thousands of cattle as well.

A similar incident in 1984 at Lake Monoun, another crater lake in western Cameroon, killed 37 people.

Volcanic gases are not usually so toxic. Carbon dioxide is being vented elsewhere in the region, but because it seeps from the ground, it releases directly into the air and so poses little danger unless one is a frog or small rabbit that wanders too close to such discharges. At Lake Nyos, the gas was released suddenly, at a single site, and remained highly concentrated.

http://www.snopes.com/horrors/freakish/smother.asp

A very interesting read and scary too!

 

[DeafSCUBA98]

i had heard that on news decades ago...