Darryl Fornatora's family hasn't heard from him since last Tuesday night.
His parents, Nancy and Gilbert Fornatora, are worried for their son who was vacationing in the city of Cabarete in the Dominican Republic.
Nancy last heard from Darryl through a text message.
It reads, "Love you. Probably five hours water time today. Call you tomorrow. Time to crash. Totally spent."
She said it's not like him to not contact her while away on vacation.
"He always calls me. Always calls or contacts me. Emails, texts, whatever it is. No more than a day would go by," Nancy said.
On Friday, the Fornatora's received a phone call from Darryl's friend, who said he hadn't seen him since Wednesday afternoon.
His parents say he was supposed to fly home from the Dominican Republic on Sunday morning.
"If he didn't make the plane, now we don't know what we're dealing with. That unknown is what can be dangerous so we don't know," Darryl's father said.
His parents have been in close contact with Leon Alter.
Leon is the founder of Crime Stoppers Republica Dominicana.
"The work for us now is finding a bread crumb that we can follow. The last sightings we had of him were on the beach," said Leon.
Leon said that he was contacted by the U.S. Embassy to get involved in the case.
He said the last sighting of the 45-year-old was last Wednesday at 3:30 p.m.
Leon is trying to track down Darryl through the GPS on his cell phone and said that Darryl's phone is active.
Authorities searched the home he was staying in and found he left behind a few items.
"He left a couple pairs of shoes and shirts, a couple books. It looks like he took his passport, his papers, his money, his credit cards, his airline ticket," Leon said.
Leon also enlisted the help of K-9s to track Darryl's scent but haven't been able to locate him yet.
They also searched the airport where Darryl was supposed to depart from Sunday morning.
Authorities in the Dominican Republic have not identified a person of interest linked to the investigation.
Some of Darryl's family members are going to the Dominican Republic on Monday to help with the search.