Investigators said the employee and a colleague were "preparing the root joint section of the blade". The component then accidentally moved in the opposite direction than planned, striking the employee, Vestas said.
Vestas stressed to Windpower Monthly that there had been no other similar incidents at the company's facilities, and precautionary measures have been put into effect to prevent it happening again.
All lifting operations will be standardised with risk assessments and work instructions, plus barriers and spotters will be used to keep any lift area clear.
The employee had been with Vestas for 16 years and was well-respected and well-liked, the company said.
Company CEO Anders Runevad paid tribute to the worker. "We are all very saddened by the accident. It's a tragedy that should not have happened, and I extend my deepest sympathies to the deceased and her family.
"This accident is a reminder to all of us in Vestas that we must always put safety first to prevent injury and loss of life – no matter where in Vestas we work . We are modifying work procedures and standards to prevent this from happening again."
The Videbaek facility operates a northern Europe sales office, a global servicing warehouse and blade assembly linked to Vestas' production facility in nearby Lem.
It has since reopened following the incident and subsequent investigation.