Police say Donald Trump Jr.'s wife opened an envelope that contained a white powder, felt ill and was taken to a New York City hospital.
They say Vanessa Trump called 911 Monday morning after opening a letter addressed to Donald Trump Jr. at their midtown Manhattan apartment. Police say she said she was coughing and felt nauseous.
The Trump Organization didn't immediately respond to a request for comment. It's unclear what the powder was.
Detectives from the New York Police Department's intelligence division and Secret Service agents are investigating. A spokeswoman for the Secret Service hasn't responded to a request for comment.
Police say a hazmat unit is also at the scene.