Two men, a 52-year-old and a 40-year-old, were taken to The Queen's Medical Center in serious condition, while a 17-year-old boy and 53-year-old man were transported in stable condition to the Wai'anae Coast Comprehensive Health Center, though the extent of their injuries was not known.

Wai'anae police said it appeared the inboard gas tank on the boat ignited and exploded, sinking the boat within minutes. Coast Guard and State Department of Land and Natural Resources officials are now at the harbor, determining how to raise the boat off the bottom of the harbor. The Coast Guard is also working to stem any pollution hazards, a spokeswoman said.

Three people were aboard the boat when the explosion happened about 6:30 a.m., and a fourth person was untying it from the pier. Johnson said one of the victims aboard the boat was thrown into the water with the force of the explosion, a second was thrown onto the pier and the third was thrown and landed in the boat.