A teacher's simple classroom exercise reminds her students "we all have baggage."

When Karen Loewe posted a photo to her Facebook page with an account of what took place in her classroom on "one of the most impactful days she ever had" in her 22 years of teaching, she never expected it to reach so many people. It's been shared more than 400,000 times.

"I was very surprised," she told "Good Morning America."

Loewe teaches seventh and eighth grade at Collinsville Middle School in Oklahoma. She got the idea for the "baggage activity" when she was looking for an something to teach the kids in her class more about kindness, she told "GMA."

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The kids were invited to read their "baggage" out loud, but it wasn't required.

"I'm 46 and I haven't been through what these kids have been through. When I was a kid I was concerned about sports and going out with friends. The stuff they are going though broke my heart," she said.

Among the "baggage" that her students shared: suicide, parents in prison, drugs in their families, and more.

Loewe told "GMA" that she's received thousands of positive comments about her post, and the best ones are from the parents of the students in her class. "Their words of encouragement and support brought me to tears," she said.

She clarified that any information she received about students who had to deal with abuse during this activity or any other time would be dealt with appropriately in the proper channels.

As for the students, she said, "they've been so much more kind to each other."