By Todd Quinones, Crystal Cranmore, Tim Jimenez and Jim Melwert

PHILADELPHIA (CBS) - A US Airways flight was diverted to Philadelphia International Airport Tuesday night after crew members reported feeling ill.

A little before 10 p.m., crew members aboard Flight 720, which left Charlotte, North Carolina and was headed to Rome, Italy, began feeling nauseous due to a strong odor in the cabin.

U.S. Airways spokesman Bill Mcglashen said, “During the early phase of the flight, two flight attendants informed our captain, as procedure, of a cabin odor. And the crew also reported that they were feeling ill.”

When the plane landed a little before 11 p.m., Mcglashen says four crew members were taken to Hospital of the University of Pennsylvania for observation; they were treated and released.

The flight departed from Philadelphia for Rome with a new crew at 2 a.m. Authorities are looking into the cause of the odor.