Leaking gas was likely to blame for an explosion that killed at least 12 people, injured 60 more and brought down part of a building in Argentina on Tuesday, state media reported Wednesday. A man who was working at the scene in the city of Rosario before the blast ignited at 9:15 a.m. local time has been taken into custody, said the Telam news agency, which cited investigator Juan Curto. The explosion gutted one multi-story residential building, and destroyed at least one other building next to it, while blowing out the windows of surrounding structures, images broadcast by CNN affiliate Canal 9 showed. A swath of white smoke and dust dominated the skyline of the city, located about 200 miles northwest of the capital, Buenos Aires. Rescuers are still searching for over a dozen people who were in the residential building at the time of the blast, local newspaper Clarin reported.