They were waxing floors, wiping down handles, and sweeping every corner. Workers don't know when students are coming back, but they're still getting ready.
A day before, announced its school reopening guidance for the upcoming academic year.
"Since the day we closed school buildings, our goal has been to return students and educators to their classrooms as soon as it is safe to do so," said Governor John Carney.
The state says it has three different reopening scenarios, based on how widespread the virus is at the time.
The first is that if there is minimal community spread in Delaware, school buildings will be able to reopen.
The second is if there are moderate levels of community spread, schools will have a hybrid model that incorporates both in-person and remote learning.
The third is if there is significant community spread, school buildings will be closed.
Parents say they don't know what the right answer is.
"Last year there was a lot of the flu and strep throat, so I was very worried, I mean I think just the normal school year has a lot of sickness," said Allison Overcash of Wilmington, whose twins are going into 4th grade.
"I think the idea of a hybrid model is a good idea and if they have to go back at half capacity and take turns with the kids to go back," said Amy Dedonato, who has five kids.
If buildings are able to open, both students and staff will have to follow strict safety guidelines while in the building.
All children grades 4 and up will be required to wear face coverings, except if a student can't for health reasons. Masks will also be strongly encouraged for students in 3rd grade and younger.
Staff will wear masks at all times.
Social distancing guidelines should be followed; and desks must be at a minimum three feet apart while students are wearing masks. Additionally, all desks should be facing the same direction.
Students will be kept in stable groups throughout the day. Both students and staff will also be asked to complete a health assessment before going to school every day.
When it comes to cleaning, schools must have high-touch surfaces, like railings, doorknobs, and bathrooms cleaned between every 15 minutes and two hours.
Stephanie Ingram, the President of Delaware State Education Association, says safety is her biggest concern.
"Just making sure that we have the products that we need to continue to keep the room clean, soap for the handwashing, sanitizer, things like that," said Ingram.
She said if it were up to her, all schools would start the year remotely.
"I think it would be great if we could all start remote to give teachers time to acclimate themselves to what it's going to look like returning to the classroom," she said.
Governor Carney said he will announce in August whether or not schools will start the year in person.