The main gas supply line to Narsingdi was damaged during construction work on a drain, according to Titas Gas authorities
A year ago this day the eight-storey building collapsed, leaving 1,135 people dead, mostly garment factory workers.
People started to gather at the site from Thursday morning. As the day passed the crowd grew leading to disruption of traffic on the highway in front of the site.
Labour organisations raised slogans demanding execution of the high-rise building's owner Sohel Rana.
Relatives and victims raised demands for compensation.
The local administration including Dhaka district's deputy commissioner and the superintendent of police paid homage at the memorial on the site around 9 am followed by labour organisations, NGOs and several garments manufacturing organisations.