Last month I wrote about K., an 11th grade District public schools student I had tutored in the spring. At the time, he had an "F" in every class and he was not attending school. He was also halfway through the final grading period. Despite that, he was going to the once-weekly study hall period where I met him every Thursday night.

We worked out deals with his teachers. They gave us the ground rules. He could pass if he completed the assignments they were prepared to give him. I watched K. work diligently on them each week, only to find out later he was still not going to school and turned in none of the work he had finished.

On the day I discovered that, he stopped coming to the study hall. He left the tutoring sessions without any explanation. He left the program's codirectors and me to wonder what had gone wrong. We wondered why he came to us and not to school. We had no answers then. We do now.

This is not a sad tale. It's one about a youth who had to face an intimidating task, the ultimate responsibility. It is also a story about a school once known as one of the the best black high schools in the country. It is about the people who went there then, and what they are doing now to help students such as K.

In December, K's girlfriend had a baby. K., at 17, was suddenly a father. His long skid to failing the second half of the 11th grade began then. He simply stopped coming to school.

A study by the High School Dropout Prevention Network of Southeast Michigan found that teen-age pregnancy was the second most common reason for dropping out of school. Most of the youths affected by that are the girls. On occasion, however, the boys are affected, too.

K. spent the remainder of the spring and summer looking for and finding work. He got a job doing grounds work, mowing lawns. It was mostly manual labor. That raises another point about potential dropouts. Although they may not have a sense of the value of an education while they are in school, they develop one rather quickly when they find so many doors of employment they cannot enter.

K. began to think about things then. With encouragement from his mother he convinced himself that if he could make it to the 11th grade, he darn sure should go ahead and graduate. There could be better jobs then.

K. and his mother went back to his high school this fall. Another deal has been worked out, one that will allow him to graduate in August if he goes to summer school. He has missed some days this fall, but he has been better about going to school.

K. attends Dunbar High School. It has a day- care center for teen-agers with children. Dunbar and K. have something else going for them as well. Years, ago it was not uncommon for a southern black family to send its teen-agers to Washington to go to Dunbar. It had that type of reputation. Now, most Dunbar students come from low-income homes.

But the alumni remember the old days, and have been generous. Nineteen of those Dunbar classes have given money to the school for scholarships and to help students such as K., who may be in a crunch for money for himself or his family. Daniel Veal, of Dunbar's class of 1943 for example, has given the school $10,000.

Dunbar's principal, Eva Rousseau, knows that tradition. She grew up two blocks from the school and was valedictorian of Dunbar's Class of 1962. She hopes to use the "public/private partnership" her school has with the Government Printing Office to interest K., whose favorite class last year was industrial arts. Rousseau has other goals, too, to bring back more potential dropouts such as K. and give them another chance.

As for K.? Well, he's made promises before, but he has more incentive this time. He has a baby to look after. "It feels okay," K. said of being a father. "I'm happy." So am I. Seeing one youth turn himself around means there are others who can do the same and parents who will finally realize the power they never thought they had.