Lawyers are seeking to prevent crew members of the containership Dali from leaving the U.S. amid ongoing litigation related to the Francis Scott Key Bridge collapse.

The crew, from India and Sri Lanka, have been on the ship since it crashed into the bridge on March 26, causing six deaths.

The City of Baltimore’s attorneys argue the crew’s testimonies are crucial for ongoing civil litigation to determine responsibility for the incident’s costs and damages.

Eight of the 21 crew members on board are scheduled to return home as early as this week, but their departure could be postponed depending on the court’s ruling regarding an emergency request to keep them in the U.S.