Answer:
When there is a natural disaster.
Step-by-step explanation:
The American Red Cross's focus is relief and disaster aid. They take blood regularly for this reasoning, when people suspect terrorism they would call 911 for a current danger and call the FBI or something along those lines for suspected danger at a later time. when there's a plane crash that needs a cause determined then the National Transportation Safety Board (NTSB) would be the ones to determine the cause of the crash. and when people want information on cancer prevention they would either contact a doctor for more information on tests to see if they have cancer. OR you would go to the American Cancer Society or even the World Health Organization (WHO).