LOCKPORT, N.Y. — The white powder found at the Niagara County Court House, which prompted an evacuation, is not a hazardous substance.

An employee opened a letter on Monday and found the substance inside. Three people were sent to the hospital for evaluation and testing and the building was evacuated.

The Niagara County haz-mat team responded to the court and later determined the substance was not harmful.

Authorities say the building is safe and is expected to reopen Tuesday.