From NBC New York:

A letter containing an unidentified substance addressed to Donald Trump Jr. was sent to a Manhattan apartment building unit that belongs to Trump Jr.’s wife, Vanessa, the president’s daughter-in-law, multiple senior law enforcement officials and city officials tell News 4 and NBC News.

A preliminary investigation suggests the substance mailed to the East 54th Street apartment is not hazardous but investigators are conducting a thorough probe out of an abundance of caution, the officials said.

Vanessa Trump and two others were taken to a hospital for observation, strictly as a precaution, after the letter was opened Monday morning. There’s no indication they suffered any injuries and their identities were not immediately released, fire officials said.

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