One person was hospitalized in a fire at a vacant two-story building Thursday morning in Chicago Lawn on the Southwest Side. The fire began about 4:30 a.m. in the 2900 block of West 63rd Street, Chicago Fire Department officials said. Firefighters extinguished the blaze about 7:45 a.m. The person was taken to Holy Cross Hospital with "very minor" injuries, officials said. Firefighters rescued someone from the second floor of the building by ladder and another person escaped from the first floor, officials said. The fire department has responded to fires at the building before, a spokesperson said. City cameras picked up the blaze which resulted in an immediate response by crews, the fire department said on X, formally known as Twitter. The building was said to have been vacant for years, and it appears squatters have been using the building "for some time," fire spokesperson Larry Langford said. The cause of the fire is under investigation but may have been caused by "illegal electrical hookups," fire officials said. Update still and box 63 street. Fire is now struck out. Building has had fires in the past and has been vacant for some time. OFI investigating reports of squatters using this building. City cameras picked up this fire leading to the extra alarm response right away pic.twitter.com/mOVTjZTMeG— Chicago Fire Media (@CFDMedia) January 9, 2025 The building sustained "substantial damage" but was still standing, Langford said.CTA rerouted 63rd Street buses as firefighters worked to put out the blaze.