A fire so large it could be seen from space engulfed parts of Mumbai’s biggest landfill site in recent days, forcing schools to shut and raising questions about the city’s waste-management practises.

The cause of the blaze in the Deonar garbage dump —where waste is piled 30 meters high in parts—is so far unknown.

The fire began on Jan. 27, producing a plume of smoke that was captured by a camera aboard a satellite belonging to the National Aeronautics and Space Administration.

Fourteen fire trucks and eight bulldozers worked for four days and nights to bring the fire under control. Parts of the landfill site that stretches over 111 hectares still smoldered Tuesday.

Rais Shaikh, a municipal official for the suburb of Govandi next to Deonar said local residents had suffered as the smoke billowed over their homes.

“There have been lots of cases of breathlessness and suffocation,” he said. “Local schools have been shut for two days.”

Air quality monitors near the site registered a steep increase in hazardous particulate matter in the days during the blaze. In one case closest to the dump, levels of fine particulate matter measuring 2.5 micrometers or less, doubled between Jan. 25 and Feb. 1. Such small particles are able to penetrate the lungs and are linked to respiratory diseases.

Deonar landfill is estimated to receive anywhere between one third to almost three quarters of the trash generated in the city, which is home to around 21 million people.

The fire threw attention on the management of waste at the site, which currently lacks a proper garbage-treatment center.

Officials at the Municipal Corporation of Greater Mumbai that administers the site did not respond to repeated requests for comment.

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 MCGM 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.

“Due to MCGM’s non-compliance and major breaches of the Concession Agreement, we have not been able to set up the processing plant,” the spokesman said.

“We were therefore forced to just receive the waste and spread it in a methodical manner without any scientific treatment,” he said.

The MCGM canceled the contract with Tatva Global on Jan. 31 citing the contractor’s failure to set up a treatment plant, according to Tatva Global.

The company says it is challenging the termination in court.