A second victim has died after this weekend’s suspected fentanyl overdose involving five people in a Waikiki hotel room.

Honolulu Police Department officials said they have opened up a second unattended death investigation after a 53-year-old male was pronounced dead at a hospital Sunday, according to HPD spokesperson Michelle Yu. Police officers and Honolulu Emergency Medical Services paramedics responded to a call at the Outrigger Reef Waikiki Beach Resort at about 6:30 a.m. regarding a possible overdose case with multiple victims.

They found five victims: a 44-year-old male who was pronounced dead at the scene; two men ages 40 and 53, who were treated and taken to a hospital in critical condition; and two women, ages 53 and 47, who were transported in serious condition. The 53-year-old man died later that afternoon at the hospital, Yu said today.

HPD said it has been confirmed that fentanyl was detected at the scene.

EMS said its personnel assisted with the death pronouncement of a 44-year-old man at the hotel. The time stamp in the first unattended death is estimated at about midnight, according to the HPD Criminal Investigation Division.

“The investigations are continuing and autopsies for both males are pending at this time,” Yu said in an email. “Anyone who has information about this case should contact HPD or Crime Stoppers Honolulu.”

Officials familiar with the case said they are looking at fentanyl as the probable cause of the deaths and illnesses.

Outrigger spokesperson Monica Salter said the case is an active investigation and the resort is working with authorities. She said the resort is not permitted to share guest information due to its privacy policy.

Fentanyl and other lab-produced synthetic opioids are driving an overdose crisis deadlier than any the U.S. has ever seen.

Since 2020, drug overdoses are now linked to more than 100,000 deaths a year nationally, with about two-thirds of them fentanyl-related. That’s more than 10 times as many drug deaths as in 1988, at the height of the crack epidemic.

Fentanyl mostly arrives in the U.S. from Mexico and is mixed into supplies of other drugs, including cocaine, heroin, methamphetamine and counterfeit oxycodone pills. Some users seek it out. Others don’t know they’re taking it.

Ingesting 2 milligrams of fentanyl can be fatal, meaning one gram could contain 500 lethal doses.

That’s driving lawmakers across the country to crack down with harsh penalties, along with adopting measures such as legalizing materials to test drug supplies for fentanyl and distributing naloxone, a drug that can reverse overdoses.

Senate Bill 671, which decriminalizes fentanyl test strips, was passed by the Hawaii Legislature this session and was sent to Gov. Josh Green on April 18.

The Associated Press contributed to this story.