DETROIT — A Southwest Airlines flight from Detroit to St. Louis was grounded after a passenger happened to notice the wing was on fire right before takeoff. <br /> <br />David Fiedor was in the back of the plane on Flight 1863 last Thursday when his spider-sense started tingling. <br /> <br />"I heard a muffled thud, similar to when the landing gear is engaging. I didn't think much of it until I looked out the window and saw the wing had flames coming out from the bottom. The flames were coming out intermittently" Fiedor told MLive. <br /> <br />The plane was carrying about 80 people Fiedor guessed, but he had the back mostly to himself. <br /> <br />Apparently no one else noticed the fire, so he got up from his seat and calmly alerted a flight attendant. <br /> <br />After first the flight attendant told Fiedor to sit down, but then she came back and saw the flames for herself. <br /> <br />She alerted the pilots, and they turned the plane back. Passengers either booked another flight or were given a refund.