The pregnant woman sat in tears on the beach next to what was believed to be the body of her brother.
The treacherous and ultimately futile journey by 80 mostly Senegalese migrants had begun in Sabratha in western Libya three days earlier, one survivor recounted.
After setting off, the boat was buffeted by rough seas and eventually ran aground on a beach in Tripoli some 70 kilometres (40 miles) to the east.
"We thought we had already arrived in Italy," one of the survivors told AFP.
Witnesses said several people had jumped from the boat to try to reach the beach but were unable to swim and drowned.
Those who made it to the shore alive included two women -- one pregnant -- and a child, and they were all in shock.
The pregnant woman sat in tears on the beach next to what was believed to be the body of her brother. She was later hospitalised.
The Libyan Red Crescent said it had recovered the bodies of five passengers from the beach on Wednesday and taken 80 people to shelters.
According to the United Nations, more than 5,000 migrants and refugees died last year while trying to cross the Mediterranean.