Sweeney skidded out of the straight after the ninth turn and looped along the next curve, crashing into the wall with her feet.
Sweeney was conscious, and she eventually got up and walked off the ice under her own power, though she was moving gingerly.
Emily Sweeney's mum, Sue (centre), watches on in horror as her daughter crashes during her luge run.
In 14th place after her third run, Sweeney was near curve nine in the final heat when she bounced up against the right wall and pinballed back and forth. She fell off the sled, then slid down the track, landing in a heap.
Emily Sweeney was thrown from her toboggan after getting sideways on the track.
It's silent at the sliding center, she's out of the track and being looked at.
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She was taken to hospital for assessment.
After the conclusion of the event she reappeared at the track flanked by several members of USA Luge and while she didn't stop for questions she did say, "I'm fine, I'm OK". According to NBC Connecticut anchor Kevin Nathan, Emily "is very sore, but she does not have any broken bones".
"It's pretty brutal, but I wanted to get the last word". Most importantly I was able to walk away.
"I know I have a lot of support and I'm sorry that's how it ended".
This was the first Olympics for Sweeney, who missed out on a spot in the 2014 Winter Games in Sochi, Russia.
Germany's Natalie Geisenberger took home the gold medal once the competition resume, while American Erin Hamlin finished sixth. According to the Associated Press, track workers tweaked the curve in the past year to make it a little more manageable.