A Prince George’s County, Maryland, couple was found dead in their hotel room in the Dominican Republic on the day they were expected to depart, and their family wants answers.

Edward Nathaniel Holmes, 63, and Cynthia Ann Day, 50, were found dead by a Bahía Príncipe hotel employee at the Playa Nueva Roman resort when they missed their checkout time on Thursday.

The couple's bodies were transported to the Dominican National Institute of Forensic Sciences for an autopsy, and according to CNN, it was determined that they died of respiratory failure and pulmonary edema, which is caused by excess fluid in the lungs.

Police also said that there were various medications meant to treat high blood pressure found in their hotel room.

Just several days prior to their death, Holmes, as reported by ABC, posted photos to Facebook of the couple on a boat ride on Tuesday with the caption, "Boat ride of a lifetime!!!" The couple had been staying at the resort since May 25, relatives said.

Holmes' daughter, Dajuan Holmes-Hamilton, told NBC4 that what transpired "should never have happened."

"We are deeply saddened by the incident at one of our hotels in La Romana, Dominican Republic, and want to express our deepest condolences to their family and friends," Bahia Principe Hotels said in a statement.

NZ beach
This is a representational image showing a beach in Golden Bay, in Nelson, New Zealand, on Sept. 8, 2018. Getty Images/Marty Melville