Here are 10 points into what led to the gas leak, the mess that followed:
Principal of Rani Jhansi Sarvodaya Kanya Vidyalaya, Manisha Vaish, said that as soon as the students complained of irritation and some of them fainted, they were taken to four nearby hospitals -- Batra, Apollo, ESI and Majithia Hospital.
The school authorities informed the parents as well as agencies concerned to control the situation. Delhi Fire Services officials were also alerted about the leak. National Disaster Response Force was immediately called to contain the leak. Seventeen ambulances from the Centralised Accident and Trauma Services (CATS) were also rushed to the school.
According to the police, a call was received at 7.35 am about some chemical leakage at customs area of Tughlaqabad depot, which is located near the schools. The chemical in the container was imported from China and was to be taken to Sonepat in Haryana.
"Around 300 children were admitted to the hospitals for treatment. No one is serious. The situation is normal now. Police will initiate legal action against the handlers for negligence," police deputy commissioner Romil Baaniya said.
Delhi Chief Minister Arvind Kejriwal and Deputy Chief Minister of Delhi Manish Sisodia met the girls. The Delhi government has ordered a magisterial probe into the incident.
The Centre has also taken note of the gas leak incident and Union minister JP Nadda instructed all Centre-run hospitals to be ready to help the victims. "Central GoI hospitals have been instructed to be ready to help all victims of Delhi gas leak incident. My prayers are with children & families," Mr Nadda tweeted.
Lieutenant Governor Anil Baijal and Opposition leader in Delhi assembly Vijender Gupta visited the victims. Mr Gupta blamed the school authorities for "negligence". He tweeted, "There were signs of gas leakage in the morning, then why didn't the school authorities stop the students from entering the school?" Delhi BJP chief Manoj Tiwari assured parents that those responsible will not be spared.
Delhi Commission for Women chairperson Swati Maliwal also met the girls at Batra hospital and demanded immediate removal of the container from the spot. "V sad. It is a man made disaster as no need for Container Depot to be in centre of Delhi. Shud b imm shifted, accountability fixed for gas leak," she tweeted.
Mr Nadda has formed a five-member committee of AIIMS doctors to deal with the situation.
The Delhi Police have registered an FIR against unknown persons under the Environment (Protection) Act.