The Department of Health and Human Services said HealthCare.gov's application and enrollment system crashed Sunday night due to an outage at the company that hosts the site. HealthCare.gov visitors received a message when trying to log on that read the "system is down at the moment.""We are experiencing technical difficulties and hope to have them resolved soon," the message continued. "Please try again later." "In a hurry? You might be able to apply faster at our Marketplace call center." Federal health officials earlier had modified the HealthCare.gov homepage to emphasize alternate ways of applying for health coverage under ObamaCare.