(CNN) Joseph Allen's brother is struggling to comprehend how his brother could have suddenly died while vacationing in the Dominican Republic.

The 55-year-old New Jersey man had just received a clean bill of health, Jason Allen told HLN. Joseph Allen worked out with a trainer and had just finished fasting for the Muslim holiday of Ramadan , his brother said.

Nevertheless, Allen's family says he was found dead in his hotel room last week, making him at least the ninth US tourist to die at a Dominican Republic resort , or after becoming ill at one, over the past 13 months.

Preliminary autopsy results suggest that he suffered from cardiac arrest. There were no signs of violence, according to the report, which Dominican authorities provided to CNN.

"I'm not a gambling man but if I had to take my chances with who would drop dead from a heart attack, it would be me," Jason Allen said.

"The idea that this is just something that just kind of happened out of the blue is just pretty difficult for me to wrap my head around."

The spate of deaths has left many Americans wondering if they should cancel their upcoming trips to the Caribbean paradise.

Officials in the Dominican Republic have called the deaths isolated events as they work to reassure travelers their country is safe

Of the nine Americans who have died at a Dominican Republic resort or after becoming ill at one since June 2018, it's not clear how many were of natural causes.

"In the last five years, over 30 million tourists have visited the Dominican Republic, but this is the first time the international media report such an alarming situation," Tourism Minister Francisco Javier Garcia said earlier this month. "These are isolated incidents and the Dominican Republic is a safe destination."

What we know about Joseph Allen's death

Allen was a Minnesota Vikings fan who put family and friends first, his younger brother said.

"He was a father figure to me. He was a perfect example to me of just a hard worker," Jason Allen said.

"He was selfless, he'd give you the shirt off his back. He helped so many people. He made so many sacrifices, even to the detriment of his own self. And that's how I want my brother to be remembered."

Joseph Allen died June 13 after falling ill in the Dominican Republic, his family says.

Allen was a repeat guest of the Hotel Terra Linda in the coastal Dominican Republic city of Sosua, Jason Allen said. The resort was Joseph Allen's spot, "his Cheers," the brother said.

When Jason Allen expressed concern over the recent shooting of baseball star David Ortiz in Santo Domingo, Joseph Allen brushed off his fears, he said.

"Everyone knew him, he knew everybody and he just never in a million years saw this coming," Jason Allen said.

Allen's friends told the family that he complained about not feeling well last Wednesday. Hotel staff found him dead in his room early Thursday after friends expressed concern that he hadn't met up with them that morning, his sister Jaimie Reed told CNN.

Jason Allen said he had no reason to believe his brother was killed intentionally. But he wonders if anything at the hotel -- the air, the drinks -- contributed to his death.

"What I do know is that I want no one and their family to endure what we're enduring right now."

Officials say Dominican Republic still safe

Dominican Republic leaders maintain the country is one of the region's top tourism destinations, with more than 6 million tourists last year, including 2.2 Americans, according to the Caribbean Tourism Organization.

Government spokesman Roberto Rodriguez Marchena put out a video calling the country the "largest, fastest growing, tourism destination of the Insular Caribbean." The spokesman said 14 million Americans have visited since 2012.

More than 41 million tourists have visited the Dominican Republic since 2012.

The largest, fastest growing, tourism destination of the insular Caribbean.

14 million came from the United States of America.#BeFairWithDR



[English Subtitled] pic.twitter.com/izm0DS4QSK — Rodríguez-Marchena (@RodrigMarchena) June 15, 2019

From 2012 to December 2018, 128 Americans died in the country from something other than natural causes, according to statistics available on the US Department of State website . The deaths include drownings, homicides, suicides, and vehicle and other accidents.

The State Department has a standing travel advisory for the Dominican Republic -- as well other highly visited Caribbean nations such as the Bahamas and Jamaica -- urging Americans to exercise increased caution because of crime.

But the department has not issued a travel alert specific to the deaths in the Dominican Republic, and American officials have not said this year's deaths were connected.

Matthew Bradley, regional security director for the risk management firm International SOS, said in a statement this month that the Dominican Republic is still a safe destination for people to visit.

8 other Americans died during resort stays, or after becoming ill there, since June 2018

On June 10, Leyla Cox, 53, died in her room at Excellence Resorts in Punta Cana, the hotel told CNN on Sunday

The hotel said the cause of death was a heart attack, citing a forensics report. CNN has not independently confirmed the claim. Excellence Resorts says it is cooperating with local and US authorities and expressed "sincere condolences to all of those affected by the recent incidents."

On May 30, staff at the Bahia Principe La Romana found Nathaniel Holmes, 63, and Cynthia Day, 49, dead. The couple had internal bleeding, including in their pancreases, Dominican authorities said. Holmes had an enlarged heart and cirrhosis of the liver -- both signs of significant pre-existing disease, the Dominican authorities said, and Day also had fluid in her brain.

Nathaniel Holmes and Cynthia Day

Miranda Schaup-Werner died in the same resort on May 25, family spokesman Jay McDonald told CNN affiliate WFMZ. She suffered from a heart attack, pulmonary edema and respiratory failure, according to a preliminary autopsy cited by the Attorney General's Office of the Dominican Republic.

Miranda Schaup-Werner

Businesswoman and "Shark Tank" TV star Barbara Corcoran said her brother died in his hotel room in the Dominican Republic in late April. John Corcoran "passed away from what is believed to be natural causes," she said in a statement.

On April 12, 67-year-old Robert Wallace died after becoming ill at the Hard Rock Hotel & Casino in Punta Cana, relatives told CNN affiliate KTXL.

"While we are deeply saddened by these incidents, and our thoughts go out to all of those affected, we, along with the general public, will be monitoring the facts as they unfold surrounding these events," the hotel said in a statement.

Last July, David Harrison, 45, died at the same hotel, according to his wife, Dawn McCoy. The cause of death was listed as a heart attack and pulmonary edema by local authorities.

And in June 2018, Yvette Monique Sport died at the Bahia Principe in Punta Cana, her sister, Felecia Nieves, told CNN. She had traveled there with a group of friends, her first vacation in eight years, Nieves said. The family is still awaiting toxicology reports.

CORRECTION: This story has been updated to correct the spelling of the city of Sosua.