Kauai police have confirmed the cause of death for a Koloa couple who were found in waters off Wailua.

An autopsy reported that Tia Obrero, 26, died of blunt force injuries and strangulation. Her husband, Michael Blackstad, 26, died of a drowning. Blackstad also sustained postmortem injuries from a shark attack, the autopsy confirmed.

Police said a bystander found Obrero unresponsive early Thursday morning along the shoreline of a beach area known as Kitchens in Wailua.

Later that morning, crews began a search for Blackstad who was believed to be with Obrero Wednesday night. He was later found dead Thursday on the rocky shoreline behind Kauai Beach Resort in Wailua.

“Our investigation has led us to believe that Michael Blackstad is responsible for the death of his wife, Tia Obrero,” police said in a news release. “We believe Michael died shortly after in waters off Wailua.”

Police said the investigation remains ongoing, however, there is no other evidence to lead to any other conclusions.

Obrero and Blackstad have two young children.