Leaking gas is likely to blame , authorities say . Firefighters swung extended ladders around to upper balconies and windows to rescue residents stranded on top floors . A man working at the site in Canal 9 before the blast ignited is taken into custody . A swath of white smoke hangs over the city , located about 200 miles from CNN . Rescuers are searching for 60 missing people , local newspaper Clarin reports .
Leaking gas is likely to blame , authorities say . A man working at the site in Canal 9 before the blast ignited is taken into custody . A swath of white smoke hangs over the city , located about 200 miles from CNN . Rescuers are searching for 60 missing people , local newspaper Clarin reports .