Six persons were on Wednesday trapped in the rubble of a four-storey building that collapsed in Onitsha, Anambra State of Nigeria.The building was located on No 7 Ezenwa Street, Onitsha.An eyewitness said the building under construction caved in around 1.45pm and that eight persons were inside it when it collapsed.The source said two persons managed to escape, while the site engineer and five labourers were trapped.It was gathered that the building was owned by a lawyer.Sympathisers blamed the collapse on the use of substandard materials for the construction.The Divisional Police Officer, Onitsha Central Police Station, Ifeanyi Iburu, led a team of security personnel and the Red Cross to the scene to coordinate the rescue efforts.Sympathisers and residents also joined in the rescue.Confirming the incident, the Chairman, Red Cross Society in Anambra State, Prof. Peter Katchy, said the rescued victims had been rushed to the hospital for medical attention.He said, “One of the persons rescued by the Red Cross is at the intensive care unit of the Holy Rosary Hospital, Waterside Onitsha, while another is at the General Hospital, Onitsha.“Four are still trapped under the rubble of the collapsed building, including the site engineer. The excavator and earth moving equipment have just arrived.”