Students returned to class at Coral Reef Senior High School for the first time Monday since a student who contracted bacterial meningitis died.
Christopher Valdes, 18, felt ill at his home Friday and was taken to Jackson Memorial Hospital South where he later died, police said.
"It's gonna be a sad day for all of us because we're all a family here," said Cristina Gomez, a friend of Valdes who took French with him last year. "You just don't expect someone like him to die because he was so lively and fun and funny, he would make the class laugh."
The school had been placed on lockdown Friday following the death. A letter to parents, which was obtained by NBC 6 South Florida, said that the student was diagnosed with meningococcal disease, a severe infection of the bloodstream caused by the bacteria Neisseria meningitidis.
The Miami-Dade Health Department said there have been no additional cases.
Health Department director Lillian Rivera said more than 20 people who came into close contact with Valdes, have been given antibiotics to prevent the disease.
Valdes died in the emergency room at Jackson South, within one hour of arriving at a hospital. Officials said the case is not related to the nationwide fungal meningitis outbreak.
"His death was abrupt, we didn't even get a chance to do blood samples on him when he was in the ER," said Rivera.
Officials sent a specimen sample from Valdes to the state lab to pinpoint the specific strain of the bacteria that killed the teenager. They were also making calls and sending out Tweets and emails in an effort to inform as many people who were his close contacts as possible.
Students were asked to wear black on Monday, to honor the memory of their classmate.
"It's hard knowing it can happen to any one of us or more of us, but we're getting through," said junior Christina Ferreiro.
On Sunday, officials with the Miami-Dade Department of Health met with parents to discuss the disease and inform them of preventative treatments.
"Senior District staff stressed to parents that all necessary measures will be taken Monday morning to safeguard the health of students at the school," school superintendent John Schuster said in a statement.
This type of meningitis is most commonly spread through kissing, sharing drinks and eating utensils. Twenty percent of people carry the bacteria that causes the potentially deadly disease, so Rivera said there is no way to determine who transmitted it to Valdes.
As parents dropped their children off for classes Monday, they said they cautioned their kids to be careful.
"Worried, in fact I told her to wash her hands and not try to get close to anybody or kissing anybody at least for the first week until they identify who are the kids that were very close to the boy that passed away," father Arnold Villar said. "These parents must be devastated, his life was in front of him, it's very sad."
"This disease is a real bad disease," said parent Miguel Acosta, who said he took his 17-year-old son to the doctor on Friday as a precaution.