Police divers have found the body of a patient who went missing after a medical helicopter crashed into the Pacific Ocean off Catalina Island near Los Angeles, bringing the death toll to three while two other people were recovering from their injuries, authorities said Friday.

Divers with the Los Angeles County Sheriff’s Department found the victim’s body Thursday in the wreckage of the helicopter after searching more than 156 square miles (404 square kilometers) over 23 hours, the Coast Guard said in a statement.

Relatives of the missing person told ABC7 that the woman was being transported from Catalina Island to the mainland for medical care after having an allergic reaction. They also said her 20-year-old son went with her in the helicopter to help translate.

The helicopter with five people aboard went down shortly after takeoff and hit the water not far from the island, officials said. The cause is not clear and the National Transportation Safety Board is investigating.

First responders pulled four people from the water on Wednesday night.

Los Angeles County Sheriff Robert Luna said that authorities were not yet identifying the victims by name. But he described the two people who died as the male pilot and a female nurse. He also said another medic and a fourth person, a man, were hospitalized.

Luna said the helicopter wreckage was about 200 feet (60 meters) deep in the water.

The helicopter’s operator, REACH Air Medical Services of Sacramento, confirmed that two of its crew members died and a third was recovering at a hospital. The company declined to provide more details.

“In the days ahead, our focus will remain on caring for our people, supporting their families and honoring the lives and service of those we have lost,” REACH said in a statement.

A memorial service was held on the island to honor the victims.

The crash came 11 days after a firefighting helicopter went down, killing two pilots in Yosemite National Park in California, and two weeks after a news helicopter crashed in Los Angeles, killing two people.

Emergency personnel were called to the Catalina crash shortly before 8 p.m. on Wednesday. Two people were pronounced dead at the scene, and two, in stable condition, were brought to hospitals on the mainland, the Los Angeles County Fire Department said.

The helicopter landed on the island shortly after 7 p.m., following a 24-minute flight from an airport in Oceanside, according to the flight tracking service Flightradar24.

The NTSB identified the aircraft as a Eurocopter EC-135-P2 and said it would be brought to a secure facility for evaluation, a board spokesperson said.

Los Angeles County Supervisor Janice Hahn called the crash a terrible tragedy.

“The people who were on board dedicated their careers to saving lives. They are heroes,” she said in a social media post.