On a typical day, the Risbergska educational center in the Swedish city of Orebro would be thrumming with students gathering to attend classes in subjects like construction, child care and Swedish for immigrants.

On Wednesday, a day after a mass shooting left at least 11 people dead and sent shock waves throughout Sweden, the school was empty as the community came to terms with the violence and some waited for news of their loved ones’ fate.

“These people who were killed here yesterday, they had dreams to become doctors, nurses, engineers, plumbers or something else,” said Shams Ulqamar Andesh, standing outside the campus where he had spent four years learning Swedish.

Mr. Andesh, 42, moved to Sweden from Afghanistan in 2012. His time at the educational center had helped him land a job as a truck driver for the national postal service, and his wife became a nurses’ aide after attending classes there.

“It was my school,” he said.

Mr. Andesh was among the handful of residents and former students who gathered near the school, placing flowers and candles on the sidewalk or staring at the building that is now the center of what Sweden’s leaders have described as the worst mass shooting in the country’s history.

The police had cordoned off the campus with blue and white tape to keep the public away from what is now a crime scene under investigation, and several officers were standing guard around the yellow brick building.