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.

Argentina’s president Cristina Fernandez is now a grandmother.

The country’s state-run news service Telam reported Monday that Nestor Ivan Kirchner was born late Sunday night at the Otamendi hospital in Buenos Aires.

The name is obvious homage to the late President Nestor Kirchner, who was Fernandez’s husband.

The news brought waves of good wishes in Argentina’s social media, but there were no official announcements by mid-day Monday, and the president’s normally busy Twitter account was silent.

Father Maximo Kirchner is active in the Campora political movement and mother Rocio Garcia is a dentist, but the couple keeps a low profile in Argentina.