An Aer Lingus flight was forced to turn around after the crew members fell ill.

Aer Lingus Flight EI139 was heading for Boston from Dublin on Sunday when it was forced to turn around about two hours and 15 minutes into the six-hour flight. The captain made the decision to land the plane and passengers were told the landing was to ensure the safety of the sick crew members, the Independent reports.

The flight was met by airport emergency services and paramedics when it landed in Dublin. The crew members that were not feeling well were taken to the hospital for observation. However none of the staff needed treatment. It is not clear what caused the illness or what sort of symptoms the crew members had.

The flight had departed from Dublin at 4:23 p.m. It was carrying 280 passengers on board. According to an Aer Lingus spokesperson, there were eight crew members on board the flight and seven of them reported that they were not feeling well. The spokesperson said that captain wasn't one of the people who were affected and no other flight crew members reported feeling ill besides the flight attendants.  None of the passengers reported feeling ill. The flight landed without incident at 8:40 p.m.

The captain and crew did not declare an emergency. The passengers were accommodated in hotels in Dublin overnight and are expected to continue on with their trip to Boston on Monday. Aer Lingus is investigating the issue.

This isn't the only incident in which a plane was forced to land after the crew members fell ill. In May, not one, but two US Airways flights were forced to make emergency landings in Dublin during flights from Venice, Italy to Philadelphia because several of the crew members got sick. It is not clear what caused the illness.