Wearing a black habit typical of nuns and white gloves, Sister Ann, who works at Florida's Archbishop Coleman F Carroll High School, was filmed cutting through the heavy branches of a tree that crashed near her school building.
"The road was blocked, we couldn't get through, and I saw someone spin in the mud and almost ... go off the road," she told CNN.
An off-duty cop with Florida's Miami Dade Police Department shot the video of the nun in action and posted it on their official page on Tuesday.
"As we recover from #HurricaneIrma, these acts of kindness remind us all that we are #OneCommunity in #MiamiDadeCounty! Thank you Sister and all of our neighbors that are working together to get through this! #MiamiDadeStrong," the department said on Facebook.
The video has over half a million views in just 12 hours of being uploaded.
"She's is truly an awesome example of a companionate servant of God. Thank you Sister Margaret Ann!" wrote Silvia Nadal.
"Prayers are great, but prayer accompanied by action is powerful," said another person.
Patrick McNicholas wrote, "God bless her but wow is it dangerous to where loose fitting clothes while using a saw of any kind. So unbelievably dangerous."
"Sister, God would not care if you put on a pare of coveralls - your habit is dangerous with a chain saw," said another Facebook user.
Hurricane Irma made landfall as a Category storm 4 in Florida forcing over 6 million people to evacuate their homes. In Caribbean islands, the extent of damage was far worse as the deadly storm destroyed most of the buildings and homes. Click for more trending news