(CNN) Five days before a Maryland couple were found dead in their hotel room in the Dominican Republic, a Pennsylvania woman collapsed and died at the same resort shortly after she checked in, a family spokesman says.

Miranda Schaup-Werner, 41, of Allentown, Pennsylvania, had just checked and enjoyed a drink from a minibar at the Bahia Principe Hotel in La Romana, family spokesman Jay McDonald told CNN affiliate WFMZ.

Schaup-Werner, who was celebrating her wedding anniversary with her husband, Dan Werner, suddenly collapsed in her hotel room, McDonald said.

"At one point, she was sitting there happily smiling and taking pictures and the next moment she was in acute pain and called out for Dan and she collapsed," McDonald said.

"He was understandably in shock, but the whole thing was just so stunning."

Paramedics were called, and first aid was provided, but Schaup-Werner died in the room, Dominican Republic National Police Col. Frank Felix Durán Mejia told CNN.

Miranda Schaup-Werner, 41, collapsed and died in her hotel room May 25.

Couple die nearly a week later

Five days later, on May 30, Maryland couple Edward Nathaniel Holmes, 63, and Cynthia Ann Day, 49, missed their scheduled checkout time at another hotel at the same resort. Hotel employees later found them dead, police said.

When Schaup-Werner's family heard about the couple's deaths, they notified the US State Department of the similarities and requested an investigation, according to McDonald. He said Schaup-Werner was healthy before her death.

"What we thought was a freak event now we don't know," he said.

The resort operator, Bahia Principe Hotels & Resorts, said there are no indications thus far of any connection between "these two unfortunate incidents" and that it followed all security protocols.

Maryland couple Edward Nathaniel Holmes, 63, and Cynthia Ann Day, 49, were found dead May 30.

3 Americans in 5 days

The two families are searching for answers after the loss of their loved ones in the same resort five days apart.

In a statement to CNN, the State Department confirmed last month's deaths of the three US citizens.

"We offer our sincerest condolences to the families for their loss," it said.

The cause of Schaup-Werner's death has not been determined, and a toxicology report is pending, but no violence was involved, Durán Mejia said.

Prosecutors are investigating the circumstances of her death, the Dominican attorney general's office said Wednesday.

As for Day and Holmes, the Dominican Republic National Police said an autopsy concluded the couple had respiratory failure and pulmonary edema, an abnormal buildup of fluid in the lungs.

Blood pressure medications were found in the room, police said; the Dominican Republic Attorney General named three medications, one of which is an opioid and another of which is an anti-inflammatory.

All 3 checked in on same day

Holmes and Day were engaged, and were from Prince George's County, Maryland, relatives told CNN affiliate WBAL . They were supposed to fly back home the day they were found.

Days before their deaths, Holmes posted Facebook photos of him and Day enjoying their time in open waters.

"Boat ride of a lifetime!!!" one caption said.

The three Americans all checked into the hotel May 25 -- the same day Schaup-Werner died, the affiliate reported . The couple were checking out five days later when they were found.

The bodies of all three Americans were transported to forensic science institutes in the Dominican Republic for examinations, officials said.

"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 after the couple's death.

La Romana is on the Caribbean coast and has a population of about 130,000.

Tourism is an important part of the Dominican Republic's economy, and its coastal resorts are a popular choice for travelers.

The tourism industry made up more than 17% of the country's economy in 2018, according to the World Travel & Tourism Council.

In 2018, about 6.5 million tourists visited the Dominican Republic, more than any other Caribbean nation, according to the Caribbean Tourism Organization. The country also attracted more tourists from the United States (2.2 million) than any other country in the Caribbean, with Jamaica (1.6 million) and the Bahamas (1.3 million) right behind, the organization said.

New York couple were killed in a March crash

The three deaths at the hotel came a couple of months after a car crash in the Dominican Republic killed two other American tourists.

The National Police said a car carrying New York tourists Orlando Moore and Portia Ravenelle plunged into the Caribbean early one morning in late March, not long after the pair left for the airport to catch a flight home.

Fishermen found Ravenelle, 52, seriously injured, and she was taken to a hospital, but she died April 4

The body of Moore, 40, was found at sea on March 31, authorities said.