6,065 others, including expectant Nigerian women and their families, were rescued by several boats owned by the Italian coastguard and international charities, Médecins Sans Frontières (MSF) and Save the Children.
417 of the badly burnt survivors, including 92 children and 70 women, were mostly Nigerians and other West Africans.
They were passengers on board four small, overcrowded dinghies which broke down about 20 miles from the Libyan coast while attempting to make the two-day journey to the Italy without adequate fuel.
About 94 of them barely alive – men, women (several pregnant) and children – saturated with fuel , skin burnt and falling from their limbs, were rescued by a ship, Dignity 1, operated by MSF,
Mostly Nigerians, they told British newspaper, The Times, that three hours into their journey from western Libya, they heard a crack as one side of the overcrowded dinghy snapped, throwing 35 people into the sea.
Two brothers aged four and five, they said, tumbled into the sea and were never found, while others grabbed jerry cans of spare fuel to keep them afloat in the water.
Some emptied the cans to make them more buoyant thus spreading the fuel on and around those in the water.
MSF rescue teams were alerted at 10:45am and the Dignity 1 was dispatched. It found a broken inflatable with six people missing and many others semi-conscious.
A seven months pregnant Nigerian woman, Joy, was rescued, coughing and sputtering blood as medical teams tried to save her life, while her semi-conscious sister Lovett lay on the vomit and faeces covered floor beside her.
Lovett told The Times that she followed Joy into the boat to look after her.
They and the others had inhaled the petrol mixed with sea water and it burnt their skin, throat and lungs.
They were just two of other heavily pregnant women and children, screaming and collapsing while being hauled off their sinking dinghy into Dignity 1.
A boy, eight, screamed in agony as the skin on his back peeled off while his fuel-sodden shirt was removed.
The survivors who could stand were stripped naked and washed down while the semi-conscious were carried into showers or bathed in buckets. The doctors battled to save the lives of the seriously injured.
According to The Times, more than 130,000 migrants who left North Africa for Europe this year were found in the same condition, while 3,502 perished at sea.
They were charged about $500 (about N157,625) for a seat on the boat by people smugglers.
Joy, resuscitated several times after her breath ceased, stopped breathing again 25 minutes later and could not be revived. She and her unborn baby died.