A Jan. 28 image of the fire at Deonar landfill in Mumbai. (NASA Earth Observatory)

Last week, a fire in the largest landfill in Mumbai sent smoke across the Indian coastal metropolis. It burned for four days, cloaking parts of the city in a thick, noxious smog. Some 70 schools were forced to close out of public health fears. Fourteen firetrucks and eight bulldozers were needed to bring the fire under control.

NASA's Earth Observatory captured the blaze from space. A more zoomed-out picture shows the extent to which the fire, streaming out of a teeming eastern suburb, was singularly discernible.

(NASA Earth Observatory)

"Fires in landfills are often particularly difficult to extinguish because they burn through methane, plastic, and other highly flammable substances," NASA noted on its website.

The cause of the fire is as yet undetermined, but local authorities suspect youthful miscreants may have set it off intentionally.

It highlights the disastrous lack of adequate waste management in Mumbai, India's biggest city, with a population of 21 million. The Deonar landfill receives a third to as much as three-quarters of all of Mumbai's garbage, yet it doesn't have a proper waste treatment facility.

The Wall Street Journal describes how grim the situation is there:

Experts say the landfill needs an underlying layer of clay to prevent toxic materials seeping into the soil and polluting the groundwater. The waste also needs to be alternated with a layer of soil to allow it to decompose properly.

Tatva Global Deonar Environment Ltd., the contractor in charge of the Deonar dump, said [Mumbai's city government] had not provided the material necessary despite agreeing to do so.

The municipal body also dumped more than 6,000 tons of waste a day in the landfill, more than double the agreed amount, a spokesman for the contractor said in an email.

A journalist at the Times of India publicized a letter written by a 6-year-old to local authorities, pleading for something to be done.

"We cannot breathe," the letter concludes.