DENVER (CBS SF) — Southwest Airlines is doing damage control after a passenger and his two children were asked to leave a Denver flight over a Twitter post.

Duff Watson and his two kids were on a flight from Denver to Minneapolis Sunday when a gate agent told him he would have to wait to board later.

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Watson is an A-List Member, which means he gets priority boarding.

Watson posted to the San Francisco-based Twitter about the allegedly rude agent, and when the airline found out, the family was asked to leave the plane.

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“He said her safety feels threatened because of what I tweeted,” Watson said.

Watson says he was forced to delete his tweet before he could fly.

Southwest apologized, and said it is investigating the incident.

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All three received $50 vouchers, but Watson says he won’t fly the airline again.