The captain of a cargo ship that collided with an oil tanker in the North Sea on Monday has been arrested. The collision of the Portuguese-flagged, German-owned Solong container ship and the US-registered Stena Immaculate oil tanker off the coast of England caused a massive fireball, and the Solong's captain was arrested on suspicion of gross negligence manslaughter because one of that ship's crew members is still missing and presumed dead, the BBC reports. The search for the man has been called off, the Guardian reports. Another 36 people were rescued, one of whom was hospitalized, NPR reports. It's still not clear what exactly went wrong to cause the collision, but media outlets are delving into environmental concerns: