Los Angeles (CNN) -- Food poisoning is the reported cause of one woman’s suspicious death aboard a United Airlines flight from JFK to LAX, but sources indicate that it may not be an isolated incident. Two days ago, 56 year-old Louise Madison, of Los Angeles, was returning home from a family visit when she was suddenly stricken with flu-like symptoms and began to vomit uncontrollably. Flight attendants attempted to perform first aid but by the time the plane made an emergency landing at LAX she was already unconscious. Other passengers on the plane reported that she appeared to have trouble breathing. Several days later, at least 10 other passengers in the same cabin reported similar symptoms and are currently under observation at their local hospitals. The WHO has not commented on the situation, nor has the White House.