The substance is thought to have been baby powder and sent in a letter from Hong Kong, according to Fire and EMS Battalion Chief Edward Smith.
Authorities determined the substance was nonhazardous, and no one was harmed or evacuated, Mr Maggiolo said.
Obama has been leasing the office space since the time he left the White House in January 2017 and it is used to conduct business while he is in the city.
Former #President Obama and his family live in the Kalorama community, which is not that far from the World Wildlife Fund headquarters building and there's no word on whether Obama was in the west end office when the letter incident was reported.
The surrounding area has been closed to traffic and will remain so until the investigation wraps up.
Vanessa Trump was rushed to the hospital after she opened the letter and found the white powder.
The incident comes just one day after President Trump's son, Donald Trump Jr., received a similar substance.
His wife, Vanessa Trump, was rushed to hospital after she opened the letter, that contained a threatening note that read: "You're an very bad person and now you get what you deserve". The incident called for FBI, Secret Service, police, and fire crews to rush to the scene.
Tests found that the substance was corn starch. The letters were sent to the offices of several politicians and media outlets and resulted in five deaths.
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