MUMBAI — Sagar Kishore Naharshetivar has been driving a van around southern India with his father lying in the back, hooked up to an oxygen tank. His father has COVID-19 and needs treatment. This past week, they've tried hospitals in three different towns, even crossing state lines from Maharashtra to Telangana.All the hospitals are full."We can't find a hospital bed for him, but I can't just take him home after all this, in his condition," Naharshetivar told local TV, speaking through a pink patterned bandana in lieu of a mask. They've been driving for 24 hours, he says. He glances back at his father, nervously. "His oxygen is running out."Some 800 miles away in the capital New Delhi, several COVID patients died on gurneys outside another hospital overnight Wednesday as relatives jostled them toward a crowded entrance. They couldn't get through the door in time.On the other side of the country in Gujarat, in western India, a man sobs over the body of his relative, a cancer patient who'd also tested positive for the coronavirus and died in the parking lot of yet another overcrowded hospital, unable to get care. Arguments erupted over who was to blame.Ghastly scenes are playing out at hospitals and clinics across India, as the country's health system collapses under a sudden spike in coronavirus cases. On Thursday, India confirmed nearly 315,000 new infections over the 24 hours preceding – the highest single-day tally for any country on any day since the pandemic began.As the health system breaks down, so does law and order: Oxygen tankers are traveling under police guard to fend off looters. Vaccines have been stolen from a hospital warehouse. And the black market trade in medical equipment has soared.People are stockpiling oxygen tanks at home, figuring there's no use in even trying to get into a hospital anymore.Social media is full of desperate pleas from Indians seeking hospital beds, oxygen, anti-viral drugs, vaccines. One veteran journalist live-tweeted his declining oxygen levels, until he died."I have never felt so desperate or helpless," Dr. Trupti Gilada said in a Facebook video she recorded of herself, weeping, as she huddled in her car outside the Mumbai hospital where she works. "We are seeing young people. We have a 35-year-old who's on a ventilator. Please pray for our patients."Why the sudden spike?On graphs, India's sudden spike in new infections shoots straight up like a wall, rather than a rising curve. The surge has bewildered Indians, coming just after their country's caseload plummeted to record lows in February."Popular belief in the country, from the public to policy-makers, was that India will not have a second wave – and unfortunately that let the guard down," says Dr. K. Srinath Reddy, an epidemiologist and public health expert who serves on a technical task force advising the Indian government on COVID-19. "It's clear that the marked opening of society – with travel, local elections, religious gatherings, weddings – led to super-spreader events. And the emergence of variants certainly added speed."Last month, India's Health Ministry announced it had detected 771 variants of the coronavirus in India, including ones first identified in the United Kingdom, South Africa and Brazil, as well as what they're calling a new "double mutant" variant. (That name may be misleading, because all variants have multiple mutations, and this one has since been given a better name: B1617.) In that variant, Indian scientists say they're studying two mutations that may increase the infectiousness of the virus and also help it evade vaccines.Fears have escalated as Indian media carry reports of fully-vaccinated people getting sick, including former Prime Minister Manmohan Singh, 88, who was hospitalized with COVID-19 nearly three weeks after his second vaccine dose April 3. As of Tuesday, his condition was stable.But experts say those fears of vaccine inefficacy are not yet backed up by science. It's unclear how ill any of those fully-vaccinated people have become, and which of the hundreds of variants circulating around India they caught. The Health Ministry says it has administered 132 million vaccine doses so far, in a population of nearly 1.4 billion. That means fewer than 10% of people have received one dose, and fewer than 2% have gotten both. On Tuesday, the Indian government released data showing that only 0.03% or 0.04% of fully-vaccinated people had tested positive for the coronavirus. India has been administering two vaccines that have shown high rates of efficacy in clinical trials: the Oxford-AstraZeneca one and another made by the Indian company Bharat Biotech."Even if this [B1617] strain is the worst case — and it would be really, really bad news for India — if other countries put in place now the kind of border measures we've seen work, we could potentially stop it going global," says Christina Pagal, a mathematician at University College London who's been tracking coronavirus variants. "We need to act now out of precaution."This week, the U.K. restricted most travel from India. The Centers for Disease Control and Prevention also told Americans to avoid all travel to India even if they've been fully-vaccinated. Both governments cited India's variants.A grim world recordIndia's daily tally announced on Thursday exceeded the previous record of 313,310 cases set by the United States on Jan. 8, according to the CDC. But with testing kits also in short supply across India, that number may represent only a fraction of the infections nationwide.Confirmed deaths from the coronavirus also broke an Indian record Thursday, with 2,104 fatalities recorded in the previous 24 hours. But deaths too may be drastically undercounted, because many of the people dying outside hospitals never got tested. Bodies are piling up in morgues. Crematoriums can't work fast enough."The second COVID-19 wave has come like a storm," Prime Minister Narendra Modi said Tuesday in a televised address to the nation.In response, Modi's government announced it would open up vaccinations on May 1 to anyone over age 18. (Until now, only those over age 45, or frontline workers, have been eligible.) But earlier this month, hundreds of clinics across the country ran out of doses. People showed up for their appointments to find signs taped to hospital gates saying their vaccination clinics were closed for lack of supply.It was a sudden turnaround for a country that has prided itself on being the world's biggest vaccine producer. India had been exporting COVID vaccines. But amid shortages, the CEO of India's largest manufacturer, the Serum Institute of India, tweeted a plea last week to President Biden, asking him to lift an export ban on raw materials. While Serum's vaccines are made in India, it imports sterile materials from the U.S. to do so. On Monday, India's government also approved a $610 million grant to help boost Serum's production.Nevertheless, opposition politicians say Modi has acted irresponsibly. In recent weeks, he presided over huge election rallies in West Bengal, one of five regions holding state elections throughout this month. On Thursday, Modi's close aide and home minister, Amit Shah, had at least three rallies scheduled, though attendance was belatedly capped at 500 people.Indian officials also refused to curb this month's Kumbh Mela, one of the largest gatherings of people in the world, where millions of Hindu faithful take a ritual dip in the Ganges River. Thousands of participants tested positive for the coronavirus in the aftermath of the event, and at least one religious leader died. Last weekend, Modi tweeted that the rest of Kumbh Mela should be held "symbolically."In his address to the nation Tuesday, Modi ruled out another national lockdown, telling Indian states that local lockdowns should be implemented only as a last resort. "Try as much as possible to protect yourselves from lockdown," Modi said. "Focus on micro-containment zones."For example, apartment buildings where people test positive for the coronavirus have been sealed off, with no one allowed to enter or exit. Police patrol their perimeter. In India's two biggest cities, Mumbai and Delhi, local lockdowns are already in place. Only essential travel is allowed, with a permit. Everyone except for frontline workers have been told to work from home. Residents aren't allowed to go for a stroll or jog, or they'll be fined.In March 2020, when coronavirus cases were relatively low in India, Modi imposed the world's biggest national lockdown. Residents were given barely four hours' notice to stay in their homes. The economic cost was painful: India's economy shrank nearly 24%, and there were cases of migrant workers starving in the streets.This week, amid fresh restrictions in Delhi, one of the capital's main bus stations was once again packed with migrant workers, trying to escape the city for their home villages. There was little physical distancing.Back in southern India, after 24 hours of driving his father from hospital to hospital, Naharshetivar doesn't know how much longer he can do this. He stares into a local TV crew's video camera and issues a plea."If you can't give my father a hospital bed, please, is there a doctor who can just give him an injection?" he begs. "Can you help my father die [without suffering]?"NPR producer Sushmita Pathak contributed to this story from Hyderabad, India. Copyright 2021 NPR. To see more, visit https://www.npr.org.