Tamil Nadu Chief Minister Jayalalithaa died at 11.30 pm on Monday at the age of 68, a day after she had suffered a cardiac arrest. She had been admitted to Apollo Hospital in Chennai on September 22 for “dehydration and fever”. In a statement, the hospital said “every possible clinical attempt was made to sustain her revival”, but that her “underlying conditions rendered her unable to recover”.

O Panneerselvam, who earlier handled the state’s finances, was sworn in as chief minister soon after her death was announced. Senior leaders of the All India Anna Dravida Munnetra Kazhagam had met at around 11 pm on Monday, where he was elected legislative leader of the AIADMK. Panneerselvam had been given charge of Jayalalithaa’s portfolios in October.

A seven-day mourning period was announced in the state, and all schools and colleges will be closed for three days. Security was increased around the chief minister’s home in the residential area of Poes Garden, while a traffic route from the hospital to her house was cleared. Her body will be kept at Rajaji Bhavan after her last rites are held in her home.

Several national leaders including Prime Minister Narendra Modi, Congress chief Sonia Gandhi, and President Pranab Mukherjee have offered their condolences. On Twitter, Modi said her death has “has left a huge void in Indian politics” and that “her concern for welfare of the poor, the women and marginalised will always be a source of inspiration”.

Earlier on Monday, the Tamil Nadu Director General of Police asked the city’s police teams to be ready to patrol the streets from 7 am in full uniform and with their cars. Huge crowds had gathered at Poes Garden and Apollo Hospital to pray for the AIADMK chief’s recovery. Chennai also saw a near-complete shutdown, as shops closed and roads were empty. Several offices and schools had shut early in the day.

Reports last week had claimed that the Dravidian leader was recovering and likely to soon be discharged from hospital. She had also been shifted out of the hospital’s critical care unit.

Apollo Hospital had issued several statements over the past two months, saying she was on respiratory support but responding well to treatment. A specialist from the United Kingdom, as well as three doctors from Delhi’s All India Institute of Medical Sciences, had been flown in to see her.

Several leaders, including Finance Minister Arun Jaitley, Opposition leader MK Stalin and the state’s acting governor C Vidyasagar Rao, had visited the hospital, even as the party maintained that the chief minister was getting better.

Her death comes during the ongoing dispute between her state and Karnataka over sharing water from the Cauvery river.

Jayalalithaa had won the state Assembly elections in May this year, becoming the first chief minister to be re-elected in Tamil Nadu in 32 years.