India is in the middle of a devastating Covid-19 surge that has set records for new infections and deaths and severely strained its healthcare system. Last week, India became the second country after the U.S. to surpass 20 million cases.

The current situation is a far cry from just five months ago, when the country had seemingly tamed a first surge of the pandemic. What’s different this time around? A look at the factors behind India’s deadly second surge:

False Sense of Security

India’s first surge peaked in September, when newly reported cases were approaching 100,000 a day. By the start of this year, that number had dropped by 80%. Meanwhile, the U.S. and Brazil, the two other countries hardest hit by Covid-19, were facing rapidly rising caseloads.

With the outbreak ebbing this winter, Indians eased up on mask-wearing and social distancing. Life was returning to normal, with visits to malls, movies and restaurants approaching pre-pandemic levels. Political rallies and religious festivals, where masses of people crowded together, potentially served as “super-spreader” events.