KELSO, Wash. -- The pastor of a Kelso church found nitroglycerin behind a donated bookshelf Wednesday, just hours before a children's Christmas party.

Pastor Hanna Peterson of First Presbyterian Church said she was cleaning when she reached behind a bookshelf and found a gooey substance in a tube.

"I picked it up and it said 'nitroglycerin,'" Peterson said. "I looked it up online just to see what it was and, yeah, it's dynamite. They use it to blow things up."

The tube, about six inches long, was brought into the church with a bookshelf that was donated in May.

"My secretary was very nervous. She was like, 'I don't think we should stay.' But I said, 'It's been here since May, it's not going to going to blow up right now,'" Peterson said.

The bomb squad was called to the church and the building was evacuated.

Peterson said she was worried the children's Christmas party, scheduled for 6 p.m., would have to be canceled.

"But they assured me they would be done by the time we needed to start to party," she said.

The bomb squad finished their job by 6:02 p.m.

Peterson said she's grateful the situation was resolved safely.

"I was thankful that nothing bad happened. I mean, it could have been fairly disastrous," Peterson said.

Kelso police said they'd like to talk with the person who donated the bookshelf, but no criminal charges will be filed because the incident appears to be a mistake.

Pastor Finds Nitroglycerin In Kelso Church