By Thatiana Diaz
July 17, 2017 11:24 AM

The family of Abigail Conner, who suffered a mysterious and tragic death at a resort in Playa del Carmen, Mexico, is seeking answers to understand how the 20-year-old was found unconscious just hours after landing.

Abigail and Austin Conner, 20 and 22, were with their mother and stepfather enjoying a vacation at the five-star all-inclusive Mexican resort Iberostar Hotel Paraíso del Mar in January.

Hours after arriving at the resort, the family from Pewaukee, Wisconsin went their separate ways: the kids left to the pool, and adults walked to the beach.

When it was time to meet, the brother and sister did not show up at the lobby nor answer the phone in their room. The couple sought help from the staff, and they received the news that Abigail and Austin had been found unconscious in the pool and taken to the hospital.

“From the moment in which the guests were found, IBEROSTAR personnel acted with urgency, following established protocols. The hotel’s onsite doctor, security personnel, and paramedics immediately responded and provided medical assistance. Per recommendation of the onsite doctor, Abigail and Austin were both transported to the hospital in ambulances,” Iberostar stated in an email to PEOPLE. 

Austin Conner was admitted and was later declared to be in stable condition, having been found face down in the pool. However, Abigail was unresponsive with a cracked collarbone. After being transferred to a hospital in Cancun and later to Broward Health Medical Center in Fort Lauderdale, FL, the family decided to withdraw her from a respirator after doctors revealed she was brain-dead on January 12, and the 20-year-old passed away. 

It’s been six months since the incident and many questions remain unanswered. The only things Austin remembers were him and his sister taking “four or five” shots at the pool bar with strangers, and then he was waking up in an ambulance, as he told the Journal Sentinel

“I’ve been in college for five years and had my fair share of drinks before,” said Austin Conner. “No way in hell I’m putting my face down in a pool and going to sleep.”

Austin’s blood-alcohol level was 0.26 while Abigail’s was 0.25, according to the toxicology reports from the Playa del Carmen medical clinic. These levels are three times the limit measured by Wisconsin law to be impaired.  

According to the newspaper, the police report contained a statement from a woman who reportedly saw the siblings having a difficult time getting out of the pool then notifying the hotel staff.   

Although the high blood-alcohol content can cause unconsciousness, the family believes there is more to it than just heavy drinking. “Somebody had to slip them some type of drug,” Bill Conner, father of Abigail and Austin, told the Journal Sentinel. His daughter was allegedly tested for opioids, cocaine and benzodiazepines with no traces detected, as reported by the publication. However, not every type of drug that can be labeled as date rape drugs were tested which include Rohypnol, Ketamine and GHB, according to the Office on Women’s Health, U.S. Department of Health and Human Services.

Iberostar added to their statement: “[The company] takes this matter very seriously and has always remained cooperative. We are deeply saddened by this incident and reiterate our deepest sympathies and condolences to the family.”

The family has hired Florentino Ramirez, of the American law firm Ramirez & Associates that has a sister office in Mexico, to unravel the mystery. 

PEOPLE reached out to the Ramirez for comment.  

On Monday, Bill Conner completed a 2,000-mile cross-country bike ride in honor of his late daughter and to bring awareness to the impact of organ donation, which he started on May 22. He has raised over $23,000 for Donate Life America, with some of the funds have been used for his bike trip.   

“I still can’t believe what happened … I’m still waiting for my daughter to walk through the door,” he said.