Florence, California (CNN) -- As scandal-plagued Miramonte Elementary School reopened Thursday with a completely new staff, Los Angeles school officials announced that ousted teachers could return to the school if they clear an ongoing investigation into faculty sexual misconduct.
Meanwhile, student attendance was only 68% Thursday, down from 90% last week, and the new faculty eased students into the dramatic changes by having them write goodbye notes to their old teachers.
Los Angeles Unified School District Superintendent John Deasy issued a statement saying those old teachers could return as a response to the Los Angeles teachers union's claim the system didn't have a plan for the school. The union said it would file a grievance on behalf of unfairly displaced teachers.
"We again communicated with the teachers today to make explicit the fact that when the investigations are complete and nothing emerges with a particular teacher, that teacher's assignment is to be Miramonte Elementary School," Deasy said in a statement.
"Further, the ridiculous claim that LAUSD does not have a plan is, of course, also not true. We are putting our plan into action as we speak, which assures student safety and support, continues an outstanding educational experience, and helps our adults," Deasy said.
Earlier Thursday, United Teachers Los Angeles President Warren Fletcher accused the school system of "making it up as they go along and the kids are paying the price."
"Parents and students want their teachers back," Fletcher said in a statement.
In a press conference outside the school, joined by parents, Fletcher added: "Parents' concerns have reached a new height as indicated by the parents standing behind me because they know that this is a huge disruption for every child and makes a tragic situation worse."
The system shut down the school Tuesday and Wednesday and removed the entire staff, from janitors to principal, after two teachers were charged with felony lewd acts with pupils. The reconstitution meant the school's 85 teachers were abruptly removed from the year-round school, which serves about 1,400 students in kindergarten through 6th grade.
Former Miramonte teacher Mark Berndt, 61, who resigned last year amid a school board's firing proceedings, was charged last week with 23 felony counts of lewd acts with pupils, a sheriff's spokesman said Wednesday. He is accused of taking bondage photos of more than two dozen students in his classroom, including some with suspected semen-filled spoons at their mouths.
Berndt is being held in lieu of $23 million bail, authorities said.
This week, a second teacher, Martin Bernard Springer, 49, of Alhambra, was charged with three felony charges of lewd acts with a girl under age 14.
Meanwhile, the new faculty and principal worked to put pupils at ease at the school, located in unincorporated Los Angeles County within the Florence-Firestone area, about 6 miles south of downtown Los Angeles.
"We're going to try to move as quickly as possible to get back to learning, to get back to any sort of routine at a school that has been anything but routine the last several days," said school system spokesman Tom Waldman.
School officials said staff will be calling families whose kids were absent Thursday.
One parent, Yolanda Rivera, pulled her daughter out of the school Thursday because she wasn't satisfied with the new staff.
"What guarantees me that those teachers aren't going to be like the last abusive teachers?" Rivera said to CNN. "They hurt us when they closed the school for two days. Why can't I keep my kid out of school?"
Edgar Flores kept his daughter out of school Thursday, and both protested outside the structure, along with more than 100 parents and children, who chanted to live guitar music, "We want, we want, our teachers back!"
"We need to hurt the school economically, and then they're going to realize that getting rid of the teachers was wrong," Flores said.
Gina Adelman, one of the school's new counselors, said teachers broke the ice with students by going around the room and asking each student what was their name, favorite color, favorite pet or pet name, and favorite toy. Adelman said she was transferred from from a middle school.
Students also wrote a formal goodbye note to their old teachers because the school was abruptly restaffed and kids weren't allowed to extend any farewells, Adelman said.
"There were several different messages, but most of them wrote, 'I will miss you' and 'Thank you for being my teacher,'" Adelman said. "One wrote, 'I will do my best,' and I thought that was lovely.
"There was one child who in the course of writing a note, completely unaided, said, 'You had to leave because something bad happened,'" Adelman added. "I said that was a very nice letter."
The school's new principal, Dolores Palacio, 66, said many of the new teachers had been laid off because of budget cuts in the past.
"These teachers are absolutely qualified. All of them were reviewed and investigated," said Palacio, a 31-year veteran of the school district who was retired until she was called into duty at Miramonte. "They are all qualified and experienced."
She chose to come out of retirement because "it's an elementary school and I'm a principal," she said. "It's a nice community, and the parents are wonderful, and what happened was to no fault of the parents or the children. If I could do something to help, I was happy to do it.
"It will take more than two days to get to know the staff really well," Palacio added. "The most important thing is that they want to be here."
Parents can visit the school any time, she said.
CNN's Stan Wilson and Casey Wian contributed to this report.