Sparks from a plasma torch are believed to have set off a fire that destroyed a 20-foot boat at Kalaeloa Barbers Point Harbor on Saturday.

The fire was first reported at 10:42 a.m. Firefighters arrived within seven minutes and had the blaze under control by 11:24 a.m., according to Honolulu Fire Department spokesman Kevin Mokulehua.

The fire started while workers below deck were using a plasma torch to cut metal. Witnesses said the fire likely started when sparks from the torch ignited foam residue nearby.

The workers were able to exit the boat before the fire caused an onboard oxygen tank to explode. No injuries were reported.

Mokulehua said firefighters prevented the fire from igniting two compressed oxygen tanks located near the boat.

An investigation into the cause of the fire is continuing. Damages have been estimated at between $250,000 and $300,000.