• Southwest Airlines and American Airlines said they were increasing service to and from Maui.
• Airlines waived fare differences and other fees for travelers headed to the island.
• 11,000 people have been evacuated from Maui, where at least 36 people died because of the Lahaina fire.

Airlines added flights to get travelers off of Maui after wildfires on the Hawaiian island killed at least 36 people and prompted evacuations.

American Airlines, Southwest Airlines and Alaska Airlines said they were adding service to help customers leave. More than 11,000 people have been flown off the island since the fires began, Ed Sniffen, the state's transportation director, told a news conference late Wednesday local time, NBC News reported. Much of the seaside town of Lahaina had burned down, after the fires were fanned by winds from a hurricane.

Hawaiian Airlines discouraged travelers without reservations from coming to Kahului Airport in Maui because of crowding.

"While we are currently operating our full schedule and have seats available on flights out of Maui today, we are concentrating our resources on transporting essential personnel and first responders," the carrier said. It also warned of possible disruptions on other routes "as we work to support essential travel needs for Maui."

An American Airlines spokeswoman said the carrier plans to operate all of the scheduled flights to and from Kahului Airport on Thursday. A spokeswoman said the carrier has "added an additional flight and upgraded an aircraft today to ensure customers evacuating OGG are able to do so."

The airline swapped out Airbus A321 narrow-body planes, which can seat about 190 passengers, for some of the flights for a Boeing 777-200, one of the largest planes in its fleet, which have 273 seats, according to American's website.

Southwest Airlines also said it was adding service to Hawaii from the U.S. mainland and intra-island flights.

United Airlines said it has canceled Thursday's inbound flights to Kahului Airport, but that it's flying aircraft in empty to pick up travelers on Maui.

Alaska Airlines said it added a "rescue flight" on Thursday, bringing the carrier's total departures from Maui to nine.

"Our main concern is the safety of our employees and guests," the airline said in a statement. "We're assessing the addition of more rescue flights to help get people off the island."

All major airlines waived fare-differences and cancellation penalties for travelers whose trips were impacted by the fires.