For about a ten-minute span, air traffic controllers lost contact with a small aircraft operated by the Mexican Navy, which was transporting a young medical patient along with seven others. Tragically, the plane crashed off the coast of Texas, resulting in at least five fatalities, as reported by Mexico’s president on Tuesday.

Initially, authorities believed the aircraft had safely reached its destination in Galveston, near Houston. However, it was later discovered that the plane had gone down on Monday afternoon, according to Mexican President Claudia Sheinbaum. The incident is currently under investigation to determine the cause. The Mexican Navy confirmed that a search-and-rescue mission in Galveston waters successfully retrieved two survivors, while one individual remains unaccounted for.

Of the eight onboard, there were four Navy officers and four civilians, including a child. Additionally, two passengers were associated with a nonprofit organization dedicated to transporting Mexican children with severe burns to a hospital in Galveston.

President Sheinbaum expressed her sympathies during a morning press conference, stating, “My condolences to the families of the sailors who unfortunately died in this accident and to the people who were traveling on board,” while refraining from speculating on the crash’s cause. “What happened is very tragic,” she added.

U.S. Coast Guard Petty Officer Luke Baker confirmed the death toll of at least five individuals from the crash, though specific identities of the victims were not disclosed.

The crash took place on Monday afternoon in a bay near the causeway connecting Galveston Island to the mainland. Emergency responders were quick to arrive at the scene, situated near the popular beach area approximately 50 miles (80 kilometers) southeast of Houston.

Sky Decker, a professional yacht captain who lives about a mile (1.6 kilometers) from the crash site, said he jumped in his boat to see if he could help. He picked up two police officers who guided him through thick fog to a nearly submerged plane. Decker jumped into the water and found a badly injured woman trapped beneath chairs and other debris.

“I couldn’t believe. She had maybe 3 inches of air gap to breathe in,” he said. “And there was jet fuel in there mixed with the water, fumes real bad. She was really fighting for her life.”

He said he also pulled out a man seated in front of her who had already died. Both were wearing civilian clothes.

It’s not immediately clear if weather was a factor. The area has been experiencing foggy conditions over the past few days, according to Cameron Batiste, a National Weather Service meteorologist. He said that at about 2:30 p.m. Monday a fog came in that had about a half-mile visibility.

Mexico’s Navy said the plane was helping with a medical mission in coordination with the Michou and Mau Foundation. In a social media post, the foundation said: “We express our deepest solidarity with the families in light of these events. We share their grief with respect and compassion, honoring their memory and reaffirming our commitment to providing humane, sensitive, and dignified care to children with burns.”

Teams from the Federal Aviation Administration and National Transportation Safety Board were at the crash site Monday, the Texas Department of Public Safety said, and a spokesperson for the NTSB said the agency was gathering information about the crash. The Galveston County Sheriff’s Office said officials from its dive team, crime scene unit, drone unit and patrol responded the crash.