Yale University has conducted an investigation on a coffee maker after several people were hospitalized. There were about three people who felt ill at the university's School of Medicine on Tuesday.

The victims were said to have felt lightheaded and dizzy on Tuesday afternoon, Deputy Fire Chief Orlando Marcano said. New Haven Register reported that officials are investigating whether the coffee maker is to blame as each person drank from the source in Sterling Hall of Medicine.

Officials were unable to immediately identify the cause for the illness. Marcano did admit that the victims drank from the same coffee machine.

They were rushed at the Yale New Haven Hospital. Yale University spokesperson Karen Peart confirmed on Wednesday that four people who fell ill had been released from the hospital on Tuesday.

Officials of the city emergency management said that the state Department of Energy and Environmental Protection (DEEP) is conducting the examination on the coffee maker and cups. NBC noted that the department also took air as well as other material samples from the scene of the incident to help determine what caused the illness.

According to Hartford Courant, DEEP announced that it was unable to detect anything that may have been the cause of the illness from the coffee maker. The department also recommended that Yale University call in an industrial hygienist to conduct further testing.

Meanwhile, Yale is one of the 17 universities that filed a brief last month to challenge President Trump's immigration ban. The higher education institutions believe that the executive order, while limited to seven countries only, have already had damaging effects on American universities.

The brief was filed in a civil action sought by the attorney general of New York and several others in the U.S. District Court for the Eastern District of New York. The order has been stayed due to the pending resolution of another case that challenged President Trump's immigration ban in Washington State.