The French teenagers were hoping to do some last-minute shopping in Cairo's historic bazaar on the eve of their return home when a bomb turned their vacation into a nightmare of screams and bloodshed.
A 17-year-old girl from the Paris suburb of Levallois-Perret died in hospital and 17 other French teenagers who were part of a tour were wounded in the attack on Sunday in the 1,500-year-old Khan al-Khalili market.
They were among 54 children from France, aged between 13 and 17, visiting one of the Egyptian capital's main tourist attractions before heading home on Monday.
The night had fallen when the bomb went off at 6:30 pm just across the square from the Hussein mosque, which dates back to 1154 AD and is among Cairo's oldest places of worship.
"There was a very powerful explosion. Then screams and blood. We all started running," said Romy Janiw, 28, one of the seven adults accompanying the teenagers.
In all, officials said, 22 people were wounded in the attack -- the first deadly violence against Westerners in Egypt since 2006.
Some reached Hussein hospital, a few hundred metres away, by foot. Others jumped into taxis to get to another medical facility.
"We were very united. We helped the wounded," Romy said.
Earlier in the day, the teenagers had toured the pyramids, rode camels and visited the archeology museum.
The group had arrived in Egypt on February 16.
During their visit, the teenagers rode jeeps in the Sinai desert and took in scuba diving lessons in the Red Sea resort of Dahab, where 20 tourists were killed in a bombing blamed on militants loyal to Al-Qaeda in April 2006.
"We are devastated. The families are terribly shocked," Levallois-Perret deputy mayor Jean-Yves Cavallini, who city organised the vacation with an association, told AFP.
A crisis team with psychologists was made available for the childrens' parents, he said.
"We had to notify the parents of the dead young woman. It was very hard," Cavallini said.
French President Nicolas Sarkozy expressed "deep sorrow" over the attack, while Prime Minister Francois Fillon said the French government "strongly condemns this criminal act whose blind violence shows its absurdity."
The French embassy and consulate moved quickly to provide assistance to the teenagers. All of the wounded, except a 17-year-old boy, are expected to be able to fly back to Paris on Monday.
The families of the girl who died and the seriously wounded young man will fly to Cairo on Monday, said another Levallois-Perret city hall official.