disastrously
adverb
UK/dɪˈzɑː.strəs.li/
US/dɪˈzæs.trəs.li/
Definitions of disastrously adverb
in a manner that causes great damage or failure; with extremely negative consequences.
The company expanded too quickly and failed disastrously as a result.
Without proper planning, the project could end disastrously.
The stock market crash affected many investors disastrously.