Of the things that worried Gwendolyn Ward when her daughter Christina walked to school, crossing the road didn’t top the list. In recent days, the 10th-grader at Seneca Valley High School had worked on a school project about teaching young children how to cross safely.

“My mind was on all these crazy people out there,” Ward said Wednesday in an interview. “You hear about young girls walking to school but never think, ‘My child’s going to get hit by a car.’ ”

On Wednesday, a tearful Ward — surrounded at her home by relatives and her daughter’s friends — spoke of the unthinkable.

At 7 that morning, Christina Morris-Ward, 15, made her way across the southbound lanes of busy Route 118 in Germantown. It was dark and overcast, and the girl was was wearing dark clothing, Montgomery County police said. She was two or three blocks from campus, where classes start at 7:25 a.m.

As she proceeded across the northbound lanes at Wisteria Drive, not far from the school, Christina was struck by a 2010 Ford Fusion. She died shortly afterward at a hospital.

Police were investigating whether the teen was using the crosswalk. They said witnesses told them that the Ford’s driver, Kevin B. Carlson, 27, of Germantown, had a green light. He remained at the scene after the incident, according to police.

“I’m going to miss her smile. I’m going to miss her taking 50 million pictures on my phone,” Ward said. “It’s just hard for me right now to bury my baby.”

Christina was studying child development. She wanted to be a pediatrician, and liked goofing around with her young nephew. She was itching to take a test soon to get her learner’s permit.

She loved to eat, friends remembered.

“She would come to my house asking for cassava leaf,” said Ramatu Kebe, another sophomore at Seneca Valley. Chicken was her favorite flavor.

She also loved Chipotle, where friends and family said they might gather for a memorial meal.

Kebe said Christina was a loyal friend to whom others turned to discuss their insecurities.

“She was trustworthy. She knows how to keep a secret,” Kebe said. “She told you like it is. She wouldn’t hold back for anybody.”

“I taught her well,” said Gwendolyn Ward.

Christina’s friends called her “the first person they would think of when they needed someone to listen to them,” said Principal Marc J. Cohen, who knew her from both Seneca Valley and his previous stint as principal at Dr. Martin Luther King Jr. Middle School in Germantown. “Almost everyone talked about her smile and her infectious laugh.”

Counselors at Seneca Valley attended Christina’s classes Wednesday to support students who knew her. Students gathered in several school offices to grieve.

Cohen said pedestrian safety is emphasized at the school, which has a large walking population and is bordered by busy roads on three sides. But Christina’s death has only heightened interest in the topic, he said, and school leaders and students are already considering a film project to increase awareness.

“We’re going to make this our issue,” Cohen said.

News of the student’s death spread throughout the county Wednesday, with some parents saying it adds to their concern over early start times at Montgomery high schools.

Recently, an online petition was started calling for a postponement of the opening bell to at least 8:15 a.m.

“It’s too early,” said Shelly McGill of Bethesda. “It’s dark out — and it’s not safe.”

The fatality comes four weeks after two students from Springbrook High School were injured when a car jumped the curb as they headed to a bus stop at 6:20 a.m. on Oct. 3 in Silver Spring.

Montgomery police said five pedestrians and one cyclist have been killed in crashes in the county this year.

Fatal crashes involving students heading to and from school are rare, said Capt. Paul Starks.

At Seneca Valley, school officials sent a letter about Christina’s death home to parents Wednesday and planned to send another, addressing safety issues, with the aid of the police department Thursday.

Christina’s social media accounts were buzzing with tributes Wednesday. “Girlfriend, can you please just text me and tell me this is not real,” read one tweet. “I need you to come back.”

“Her Facebook and Twitter are on fire,” her mother said. “I can’t look at it.”

For now, she had her own memories of the happy, goofy daughter she loved.

“We’ll be in the car, and she’ll be singing to me and holding my hand,” said Ward.

Jennifer Jenkins contributed to this report.