Baby girl (1) pulled out alive three days after Kenya building collapse
* At least 21 confirmed dead in collapse so far
* Expanding Nairobi struggles to build enough homes
* Collapsed building had been earmarked for demolition
* African cities grow as farm migrants seek work
At least 21 people have so far been confirmed dead after the six-storey residential block in Nairobi's poor Huruma district crumbled on Friday night.
Police are questioning the owners after President Uhuru Kenyatta ordered them detained.
"The child, who had been buried for about 80 hours, was found in a bucket wrapped in a blanket. She appeared dehydrated, and with no visible physical injuries," the Kenya Red Cross said in a statement.
The fate of her parents was not clear. The girl was being treated in hospital.
The collapse of the building was the latest such disaster in a fast expanding African city that is struggling to build homes fast enough.
Like many other cities in Africa, the population of Nairobi has climbed dramatically in recent years. The Kenyan capital had almost 3.5 million people in 2011, about a third bigger than a decade earlier, according to U.N. figures.
Governments have struggled to provide basic infrastructure and bureaucratic processes to ensure planning rules are met.
Many Kenyans who come to the city in search of work end up in one of several slums, such as Kibera, made up of makeshift homes of wood and corrugated iron sheets.
Others live in slightly better off but still poor districts, like Huruma, where concrete buildings have risen rapidly amid potholed roads and ropey power supplies. Heavy rains have caused other collapses in Nairobi but without such high death tolls.
The Interior Ministry said the Huruma building had been earmarked for demolition as it was built close to a river, but the order had not been carried out by local officials. It urged developers to adhere to safety standards
After visiting the site on Saturday, Kenya's president ordered other buildings to be surveyed to ensure they were safe.
Rescue workers had said on Monday that the chances of finding more survivors was unlikely. About 136 people have already been saved from the wreck.
Dozens of other people are still listed as missing, Red Cross spokeswoman Arnolda Shiundu said, adding it was not clear how many of those had escaped but had not yet been traced.
Similar disasters have afflicted other African conurbations. In 2014, a church in Lagos, one of Africa's biggest cities, collapsed killing 115 people. A Nigerian coroner last year blamed poor construction.
Poor and illegal construction has also often been blamed for the crumbling of apartment blocks in Egypt, where almost all Egyptians are crammed into the crowded Nile Valley and buildings are often extended with extra floors piled on top.