Twelve people, including a doctor, died at Delhi's Batra Hospital on Saturday after the facility ran out of medical oxygen - for the second time in the space of a week - at 11.45 am. The hospital's Executive Director, Dr Sudhanshu Bankata, said the next 24 hours would be "critical" and that more deaths due to oxygen shortage could not be ruled out. "These are patients whose oxygen levels sank when supply was low... it is hard to revive such patients. The next 24-48 are hours critical and death toll could be higher," Dr Bankata told NDTV.