Five people died Sunday in an apparent murder-suicide at a home in Hawaii, according to police.

In a news conference held Sunday, Lt. Deena Thoemmes said Honolulu police responded to a call that morning from an anonymous caller who heard an argument at a home in Manoa, a residential area adjacent to downtown Honolulu, located on Hawaii’s Oahu island.

Police initially arrived at the home around 8:30 a.m. but had no cause to enter. They returned around 9:15 after receiving another call, and spoke with the caller.

Once inside the home, police found four people people had been fatally stabbed: An adult female, a 17-year-old, a 12-year-old and a 10-year-old. The husband was also found dead, and Thoemmes said his death is still under investigation when asked if he had stabbed himself.

Based on the evidence found at the scene and the investigation, Thoemmes said the man appeared to have killed the woman and three children with a knife found at the scene. His motive is still under investigation.

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The ages of the adults was not immediately known, and the identities of all five of the people will be released by the medical examiner’s office.

The five deaths mark the state’s worst mass killings since the Xerox murders on Nov. 2, 1999, when Bryan Koji Uyesugi fatally shot seven co-workers, including his supervisor, Chief Joe Logan said.

Contributing: Associated Press.