Question about Jurassic Park Rex

Was that whole “Trexes are attracted to flares” thing a based on palaeontology at the time, or a plot device? Or did they specifically engineer that as a last resort just in case the Trex broke out?

Was that whole “Trexes are attracted to flares” thing a based on palaeontology at the time, or a plot device? Or did they specifically engineer that as a last resort just in case the Trex broke out?