A piece of “unremarkable” mail opened by Gov. M. Jodi Rell’s staff released an odor that sent two of the six employees in her fourth floor office to the hospital, Capitol Police Chief Michael Fallon said Wednesday evening.

Fallon said the state police major crimes unit is investigating where the letter came from and the Department of Public Health is testing the envelope to determine what caused the odor. He said there was no powder or white substance in the envelope, just an odor that caused the employee who opened it to experience a scratchy throat and start itching.

Fallon said two employees were taken to the hospital and all six employees were decontaminated at the Capitol. Everyone from the Department of Environmental Protection to the Federal Bureau of Investigations was involved in investigating the incident, which occured around 2:30 p.m. The fourth floor offices on the West side of the Capitol were evacuated and the Capitol was locked down early Wednesday. Rell remained in her office on the second floor until after 6:30 p.m.