As many as eight people are feared to have been killed when the buildings crumbled in a matter of seconds on Monday morning in Noailles, a working-class district in the heart of the Mediterranean port city.
Several other buildings in the narrow street have been evacuated amid fears of further collapse as “all the buildings lean against each other” on the sloping street, a firefighter involved in the search for survivors said.
Small groups of the 105 residents ordered to leave were being escorted by firefighters back inside the buildings to fetch some of their belongings.
“It brings back my memories of the war, when I was a child,” said Yoanna, a 27-year-old Lebanese woman.
“I've never had to leave an apartment so quickly.”
After searching the rubble for a second night, rescuers have retrieved the bodies of four men and two women, prosecutor Xavier Tarabeux told AFP.
“We're working hard, so there's still hope,” a rescue worker told AFP at dawn on Wednesday as his team continued to search the wreckage with sniffer dogs.
But Interior Minister Christophe Castaner had already warned on Monday evening that there was “little chance of finding air pockets” in the rubble.
'People died for nothing'
The difficult rescue operation — and the fragility of the buildings — became clear when a third adjoining block partially collapsed on Monday evening.
Google Maps images taken in recent months showed large cracks in the facades of the buildings, only one of which was occupied.
Those on either side were in such a poor state that they had been declared off limits and boarded up for a number of years.
City officials said building experts inspected the occupied building on October 18 and shoring up work was then carried out before residents were allowed back in.
Residents say structural problems were widely known, but city officials did little when alerted about them.
“Everybody knew about the problems,” said Patrick Lacoste, a spokesman for a local housing action group. “People died for nothing.”
Adama, originally from the Comoro Islands, said: “It's only blacks and Arabs living here, so nobody cares.”
“I pay rent — 380 euros ($430) a month — and I even pay a municipal housing tax. But you've seen the state of the buildings,” the young man said.
Sophie Dorbeaux told AFP she had left the now-demolished block on Sunday night to stay with her parents because her door, like several others, was not opening or closing properly.
“The walls had been moving for several weeks and cracks had appeared,” the 25-year-old philosophy student said.
“It could have been me,” she added, visibly shaken.
6,000 properties at risk
Castaner told lawmakers in Paris on Tuesday that he had ordered a building-by-building audit before an launching an “ambitious programme for ensuring safe conditions” in coordination with Marseille authorities.
“Nearly 6,000 properties have been identified as at risk” in the city, he said, representing some 44,000 lodgings in lower-class neighbourhoods.
Marseille city authorities, who have evacuated and rehoused 105 residents from nearby buildings, believe heavy rain may have contributed to the collapse.
But critics say Marseille's poorest have long lived in unacceptable conditions.
The neighbourhood struck by the disaster is home to many buildings in a similarly dilapidated condition, some of them run by slum landlords.
Local residents called for a meeting Wednesday evening to demand better housing conditions.
Marseille authorities began a vast upgrade plan for the city centre in 2011.
But a 2015 government report said about 100,000 Marseille residents were living in housing that was dangerous to their health or security.
“It's unthinkable that such things happen in our time,” said Christian Gouverneur, who owns a flat across the road from the disaster site.