Students at the Southern California high school where a popular photography teacher hung herself returned to class Tuesday, trying to process the confusion and grief over her death.

As classes began, a school administrator used a loudspeaker Tuesday to tell students they would all miss Jillian Jacobson and must stay united. Later, teachers spoke with students and counselors were available in the school's theater.

At Jacobson's classroom, the door remained closed. Students say a picture was placed outside, along with notes and bouquets of flowers.

Students and a teacher found Jacobson hanging from her classroom's ceiling Monday morning at El Dorado High School in Placentia. Paramedics responded but were unable to revive the 31-year-old teacher.

Placentia police say no suicide note has been found.