The U.S. airline business is experiencing a distressing downturn. On Wednesday, for example, Delta, American and Southwest shredded their earnings forecasts as their travel demand took an enormous hit.

Recent warnings from the big airlines suggest a troubling trend for the industry. Delta, American and United Airlines have all acknowledged softening demand for air travel, pointing to a decline in consumer and corporate confidence.

Airlines are slashing their financial outlooks. Delta has lowered its profit estimates for the first quarter, and American expects a bigger-than-expected loss. Declining revenues have prompted Southwest to adapt with new fees.

Recent tragic events have rocked the airline industry. The midair collision of an American Airlines flight has put a damper on bookings and contributed to the more general decline in demand.

The decline in travel demand extends far beyond airlines. Reduced consumer spending is manifesting in a downturn across various sectors. Corporations are cutting back on travel budgets, which impacts airline revenue streams.

To survive these difficult times, airlines need to adjust. They could also prioritize cost-saving and seek new sources of revenue through improved loyalty schemes. Possible consolidation may further change the industry as well.

The road to recovery for the U.S. airline industry remains uncertain. Airlines are tasked with innovating to boost consumer confidence and restore travel demand.