Authorities are investigating a suspicious substance in an envelope after three Marines were hospitalized at Joint Base Myer-Henderson Hall in Arlingon, Va., on Tuesday.
After the envelope was opened around 3 p.m., 11 people began to feel ill. The building was evacuated, according to a statement by base officials.
Following an evaluation of the 11 personnel, three were transported to a hospital for further medical evaluations. All three were released at approximately 10 p.m.
Base officials worked with local HAZMAT teams, NCIS and the FBI, and the building was screened and cleared. All personnel were allowed to report to work on Wednesday.
NCIS and the FBI are conducting a joint investigation, officials said.