The gas leak from a chemical plant in Visakhapatnam in which at least 11 people were killed and 1,000 affected on Thursday is one in a long list of industrial accidents resulting from poisonous gases seeping into the air.
The December 1984 Bhopal tragedy in which more than than 3,000 people were killed when methyl isocyanate leaked out is the world's worst industrial disaster.
Here are other gas leaks that made headlines in the last few years:
Bhilai, Chhattisgarh: On June 12, 2014, there was a leak in a methane gas pipeline at the Bhilai plant of Steel Authority Of India Limited. Six people, including two deputy general managers of the company, were killed and over 50 injured.
Nagaram, Andhra Pradesh: On June 27, 2014, a massive fire broke out following a blast in Gas Authority of India Limited's plant, killing 29 people and injuring 10. The 18-inch underground pipeline, designed to supply gas to the Lanco power plant, was used for transporting wet gas having condensate/water. This corroded the pipe and led to a gas leak. An ignition triggered the explosion and the subsequent fire.
Mangaluru, Karnataka: On November 17, 2016, a gas leak in an HPCL running between Mangaluru-Hassan-Mysuru and Solur created panic in villages in the area. Several people were reportedly hospitalised after they inhaled the gas. The leak was spotted early on and was contained before much damage.
Kanpur, Uttar Pradesh: At least five people were killed and several injured in an explosion caused by an ammonia gas leak in the Katiyar cold storage in Kanpur on March 15, 2017. The explosion caused the roof of the building to collapse, trapping several people.
Delhi: About 450 girl students were hospitalised on May 6, 2017, after toxic fumes spread due to chemical leakage at a container depot near two schools in south-east Delhi's Tughlaqabad area. The chemical, 'chloro methyl pyridine' is an eye and respiratory irritant and causes redness and watering of eyes along with respiratory symptoms like sneezing, coughing or difficulty in breathing.
Por village, Gujarat: At least 20 people were hospitalised after the valve of a chlorine gas cylinder in a drinking water tank in Gujarat's Por village developed a leak on April 13, 2017. Those exposed to the gas complained of eye and throat irritation.
Belur, Karnataka: At least 25 people were reportedly hospitalised after inhaling chlorine gas that leaked from a water treatment plant on the outskirts of Belur on May 16, 2017. Those who inhaled the gas showed symptoms like breathlessness, nausea and burning sensation in the throat.
Bhilai, Chhattisgarh: On October 9, 2018, 11 people died and 14 injured in a blast at the Bhilai Steel Plant. The blast took place in a pipeline near the coke oven section at the steel plant during a maintenance job.
Valsad, Gujarat: Over 40 workers of a glass manufacturing factory in Gujarat's Valsad district were hospitalised following a leakage of chlorine gas in an adjacent chemical company on December 20, 2018.