San Bernardino students celebrate first day of schoolThousands of students returned to classrooms Monday as the new school year began in the San Bernardino City Unified School District. Thousands of students returned to classrooms Monday as the new school year began in the San Bernardino City Unified School District. Thousands of students returned to classrooms Monday as the new school year began in the San Bernardino City Unified School District. Thousands of students returned to classrooms Monday as the new school year began in the San Bernardino City Unified School District. SAN BERNARDINO (KABC) -- Thousands of students returned to classrooms Monday as the new school year began in the San Bernardino City Unified School District.