A three-storey building collapsed in Palakkad, 340 km north of Thiruvanthapuram on Thursday, trapping many under its debris. At least seven people were rescued from the rubble, police said.Police said the accident took place when workers were replacing the concrete beam of the old building.The state government has directed the district collector to co-ordinate the rescue operation. “Rescue work is in full swing. Seven people have been rescued so far. Hope we will be able to remove the rubble by the evening,” said Palakkad MLA Shafi Parambhil. Although no casualty has been reported, local people said many were feared trapped under debris. Rescue operations were hindered by the presence of large number of people at the site of the collapse.Heavy rains have lashed Kerala for the past week but it is not known if the rain was responsible for the collapse.