A distracted ship operator was texting on his phone instead of doing his lookout duty when two large ships collided off the coast of Louisiana last July, a federal agency investigation has found.

The collision — which occurred in "good visibility, daylight and fair-weather conditions" — happened when the bulk carrier Bunun Queen crashed into the supply vessel Thunder, flooding the deck and resulting in $12 million total damage to both ships, according to a National Transportation Safety Board report released late last month.

The Thunder "sustained substantial damage" and most of its 18-member crew were evacuated. No injuries were reported from the July 23, 2022, incident.

The probable cause of the accident was the result of the Thunder watch officer's distraction due to cell phone use, the NTSB report concluded.

Investigators found that the officer made a personal call that lasted a minute and used "voice dictation on his phone to send multiple text messages, all of which were personal in nature."

But the NTSB also blamed the Bunun Queen watch officers for not keeping a proper lookout because they were distracted with other tasks.

"Using cell phones and other personal electronic devices has been demonstrated to be visually, manually, and cognitively distracted," the NTSB report said. "Nonoperational use of cell phones and other wireless electronic devices by on-duty crewmembers in safety-critical positions has been a factor in accidents in all transportation modes."