Frontier, Southwest and Spirit airlines are providing free air travel to Denver for families of the Aurora shooting victims who live out-of-state. They join United, which confirmed Thursday that it was providing travel assistance to families.

“We have been providing free travel for immediate family members of the victims,” Frontier spokeswoman Lindsey Carpenter said Friday.

Southwest spokeswoman Michelle Agnew said the airline is working closely with the Colorado Organization for Victim Assistance to receive requests from the families and to book their travel.

“Our hearts go out to those affected by the theater shooting,”Agnew said. “Anytime there is a tragic event in a community we serve, we quickly look for ways to give our support.

Other airlines contacted by The Denver Post did not return messages.