The most critical lesson x learned as a student in Tanzania came during a graduation ceremony when she was 14. A teacher noted that several students had left school early to marry. The teacher then shared an emergency phone number for any girl pushed into marriage. "I wrote down the number and went home," said x, now 15 years old. She held down to that number. x comes from a village in the country's southeastern x area. One day, her mother informed her she soon would be married to a stranger. x burst into tears. She cried out: "I don't want to be married!" But her mother ignored her. She said that the man was young and a good person. x's grandmother gave her a wireless phone to communicate with the man she was to marry. Instead, x used it to plan her escape. "Immediately, I called the police officers. They asked me to get the man's name and the wedding day," x remembered. Once she had a few details from her mother and passed them along, police notified a local official. The official showed up at the family\'s home the day before the planned marriage. He asked the girl whether she wanted to marry. "When I said no, he halted the ceremony," she said of the official. A local social worker made plans for the girl to move to a shelter in x, about 325 kilometers to the north. x was able to avoid an unwanted marriage. That is not the case for many young women in African countries below the Sahara Desert. The area has the world's highest number of child marriages. Every year, more than three million girls there marry before they turn 18, the United Nations Children's Fund reports. The area also has some of the highest rater of boy child marriage, UNICEF noted in a spring 2019 report. Girls are pushed into early unions by custom or a lack of good possibilities, research shows. Children most at risk of early marriage come from poor families in rural areas and have limited access to education. In Sub-Saharan Africa, seven in ten girls finish primary school, but only four in ten complete the lower secondary level, World Bank researchers say. In a November 2018 report, the World Bank said women with secondary education are more likely to work, and they earn twice as much as those with no education. The report estimates that child marriage could cause a collective 63 billion dollars in lost earnings over the lifetimes of women in 12 African countries. An African Union campaign to end child marriage began in 2014. "It has created quite a lot of buds on the continent," said x with the international coalition, Girls Not Brides. The campaign has targeted 30 countries, including Niger and Tanzania. It tries to educate people on the personal and societal good of delaying marriage. It calls for supporting legal and policy actions to protect human rights and build a social movement. And x says the A.U. has shown respect for traditional and religious leaders. "They are the ones who can lead the agenda of changing social norms and the value that is placed on the girl," she said. In Tanzania, where x left her family to avoid marriage, about one third of girls marry by 18, says Girls Not Brides. As a result, just more than 25% of all girls complete secondary school. In a January report on Tanzania, the World Bank said that ending child marriage and early child-bearing would slow the country's population growth. This would reduce the demand for social services as well as pressure on infrastructure. The country could see savings of up to five billion dollars a year by 2030 as a result, the report said. The Tanzanian government and courts are struggling with child marriage. A legal action led its High Court to strike two parts of the country's marriage law in 2016. The action raised girls' lowest marriageable age to 18. Before that, the age was 15. But the government appealed the decision last year, saying the lower age protected girls who become pregnant when they are not married. A ruling is expected soon. For now, the government expels pregnant girls from school. Despite the unsettled law, Tanzanian girls like x have been able to get help when faced with an unwanted marriage. They, like x, can turn to the Federal Tanzania Police Force. It has trained teams across the country to deal with sensitively with reports of domestic or sexual violence, human trafficking or threats to children. Officials can remove children from a situation they believe is unsafe. x went to a x shelter run by x Women's Health and Development. The non-governmental organization also operates drop-in centers for at-risk girls and women. x has worked with counselors to recover from trauma. She is taking class in computer science, finances, cooking and textile arts. "My dream is to become a great fashion designer," x says. x says x has become an inspiration. She says x helped to start a girls' group that meet daily to support the goals of education, female empowerment and a greater say in whether and when to marry. Communication with x's family is limited. The girl's mother sends messages through a social worker. "The goal is to reconnect the family but delay an unwanted union," says x, who runs the shelter. She adds rushing these children to marry s to curtail their dreams.