Akhilesh Bhargava spent his 30th birthday clinging to a tree as flood waters below him tore through a Mumbai street, sweeping along the bodies of children, logs and the debris of a city battered by rain.

Now, three days after India's highest ever recorded one-day rainfall, he counts himself among the lucky -- another survivor rescued by the thousands of Mumbai residents who risked their lives to help those in need.

Roads turned into rivers, telephones went silent, trains stopped running and aircraft couldn't take off after suburban neighborhoods in India's financial capital were pounded on Tuesday by 94 cm of torrential rain.

"It was horrifying. I saw children float past me and logs of wood and branches," Bhargava said on Thursday, still recovering from his night-long ordeal, his body covered with purplish bruises and nursing torn ligaments in his leg. "You didn't know what was going to hit you."

His nightmare began on Tuesday evening when he decided to head home with a cousin after four hours of incessant rain began flooding the basement office where he runs his packaging business, off a busy road leading to Mumbai's international airport in suburban Sahar.

• Terrible Tuesday: Mumbai copes with a calamity

Outside, he grabbed onto a rope that residents had tied across the road to help people wade through the neck-deep water.

"One minute we were hanging on to the rope and the next my cousin slipped and his head went under water," Bhargava said, shuddering. "I tried to pull him out with one hand, but my legs gave way."

"I kept shouting for help, but people couldn't hear me above the roar of the water."

As he fought to stay above water, five pairs of hands grabbed him and pulled him onto a tree by the side of the road.

He spent the night with the strangers who had saved his life. They all watched helplessly as bodies washed past them. "We wanted to help them, but if I had let go, I would have been finished."

His cousin too managed to stay afloat, and was pulled to safety by people further along the road.

This hectic cosmopolitan city may be famed across Asia for its movie industry dominated by hip-swaying musicals, its wealthy stockbrokers and its powerful business clans, but this week it proved something else: It looks after its own.

The people who rescued Bhargava and his cousin were among the still-nameless Mumbai residents who offered help despite the dangers, or who opened their homes to strangers, or fed tea and biscuits to people wading past in waist-deep water.

Even five-star hotels joined in, offering cavernous rooms to bedraggled commuters and residents of surrounding shanties.

"One hotel opened up its convention hall and gave medicines, food, water and warm blankets to kids from the nearby slum. There were at least 500 poor people in that huge room," said Ravi Prasad, a garment exporter who had gone into the hotel to buy food.

On Thursday, Bhargava shook his head as he stood on the same street, still flooded in parts, but now packed with cars honking to inch ahead. "You can't imagine the force of water was so great here on a main Mumbai road."

While Bhargava fought to hold onto the tree, in a neighbouring suburb his wife and two young children, aged two and five narrowly escaped being drowned.

The car they were traveling in, with cake and snacks to surprise Bhargava in his office, filled with flood water in a matter of minutes.

"I could barely see my son, the water inside the car was that high," sighed Pooja, returning from a temple on Thursday after giving thanks for her family's safety. "When we opened the car door and got out, the car just sank."

Employees in a nearby office block rushed out to help the family to safety. She later walked more than five hours to get home, carrying her children with the help of a family friend.

It was only Wednesday morning that she managed to reach her husband. "I had no idea where Akhilesh was till we got through to a friend whose place he managed to get to," she said.

The family has postponed all birthday celebrations. "We're still recovering. To have survived is celebration enough," said Bhargava.

His wife said she gave thanks at the temple to the five people who saved her husband's life. She wishes she could thank them personally, but doesn't even know their names.

Also Read: Terrible Tuesday: Mumbai copes with a calamity