Ransomware is highly destructive & disrupted ER support for a short period of time, as documented below

http://www.darkreading.com/vulnerabilities—threats/ransomware-attack-forced-ohio-hospital-system-to-divert-er-patients-/d/d-id/1333333

http://www.timesleaderonline.com/news/local-news/2018/11/hospitals-patient-information-safe-in-eorh-ovmc-computer-attack/

A ransomware attack that hit computer systems at the East Ohio Regional Hospital and Ohio Valley Medical Center reportedly disrupted the hospitals’ emergency rooms. The attack hit the evening of Friday, Nov. 23, leaving the hospitals unable to accept ER patients via emergency responders. Those patients were diverted to other area hospital emergency rooms, The Times Ledger newspaper reported.

Karin Janiszewski, director of marketing and public relations for the hospitals, told the paper that the two hospitals hit by ransomware were able to handle walk-in ER patients, and that the IT team had hoped to have the attack “resolved” by Sunday, Nov. 25. “We have redundant security, so the attack was able to get through the first layer but not the second layer,” she said. “There has been no patient information breach.”