Delta Airlines broke ground on a $160 million renovation at LaGuardia Airport last week. The improvements include building a connector between Terminals C and D. In addition, the carrier is investing about $1.2 billion at JFK Airport to tear down Terminal 3, the old Pan American terminal, and expand into a renovated Terminal 4. Other airlines have spent big on New York’s airports in recent years. American Airlines put $1.3 billion into Terminal 8 at JFK Airport, a project completed in 2007. United Airlines spent about $2 billion on renovations at Newark Airport, and JetBlue spent $743 million remodeling Terminal 5 at JFK, which was completed in 2008.