(RNN) - Vanessa Trump, the wife of Donald Trump, Jr., was taken to a hospital in New York after opening a letter that contained an unknown white powder inside, the NYPD said.
Police said she was taken to New York Presbyterian Weill Cornell Medical Center as a precaution. A preliminary test indicated the powder wasn't dangerous, a spokesman told the Associated Press.
Vanessa Trump called 911 Monday after opening the letter, addressed to her husband, at their Manhattan apartment. Police said she reported feeling nauseous.
A hazmat unit responded, and the NYPD and Secret Service are investigating the incident. The FDNY told CNN that three people had been transported to the hospital but did not provide any additional information.
On Twitter, Trump Jr., shared his feelings about the experience.
He also made it a point to thank the first responders who came to their aid.
Ivanka Trump, Vanessa's sister-in-law, spoke out about the incident as well.
Vanessa herself thanked first responders and law enforcement.
In March 2016, the home of Donald Trump Jr.'s brother, Eric Trump, received a threatening letter containing white powder. Police determined the powder in that case was harmless, as well.