The captain of a cargo ship that collided with an oil tanker in the North Sea has been charged with gross negligence manslaughter. The Portuguese-flagged Solong and US-registered tanker Stena Immaculate crashed off the East Yorkshire coast at about 10:00 GMT on Monday. A crew member of the Solong is missing and presumed dead.

The captain of the Solong cargo ship who was arrested after crashing into an oil tanker off the English coast is a Russian national, the vessel’s owner said Wednesday, as maritime experts search for answers.

British authorities have arrested the captain of a cargo ship as they investigate the cause of a fatal crash between the vessel and an oil tanker shipping jet fuel for the U.S. military in the North Sea.