A massive deep sea research ship that toppled over this week in an incident that left 35 people injured was “unlikely” to have turned over as a result of high winds, according to a marine expert. RV Petrel—a U.S. Navy ship once owned by Microsoft co-founder Paul Allen—keeled over in a dry dock in Scotland on Wednesday. Ten of those injured in the incident were still hospitalized as of Thursday. Reports suggested high winds may have led to the disaster, but Dr Iraklis Lazakis of the University of Strathclyde’s Department of Naval Architecture told the BBC that seems improbable. “It’s very, very unusual for such accidents to happen,” Lazakis said. “The dry dock is like a dug-up big ditch or shelf where the ship sits down with all its structure and weight. So it might have been unlikely just to be tipped over by the wind. It’s something that really needs to be investigated very, very thoroughly in order to make sure what was the original cause of the whole accident, but I have to say it is a very, very unusual thing to happen within a dry dock.”