New DelhiDangerous buildings in Satya Niketan are under the scanner. (Vipin Kumar/HT)Police on Friday arrested 27-year-old Shubham Tyagi, one of the operators of Hostel Daze paying guest (PG) accommodation, who has been on the run since September 6, when the five-storey building in Satya Niketan collapsed and left seven people dead.Tyagi surrendered at the South Campus police station on Friday morning, following which he was arrested and produced in court, and was sent to two days of police custody. His arrest comes days after the police arrested his business partner and other PG operator Sudhanshu Loveneesh, who leased the building from its owners.Police said they had been conducting raids in Rajasthan, Uttar Pradesh and Haryana to trace Tyagi. Investigators said they are checking Loveneesh’s phone to identify people he may have called or texted to help Tyagi evade arrest, a senior police officer said. “The two will be jointly interrogated. We have to establish a sequence of events. As per our initial enquiry, both the men had been informed by a labourer that the structure of the building is weak and any repair work will be a risk. But they did not take any action,” the officer, who did not wish to be named, said.Tyagi’s arrest takes the total number of arrests in the case to six. A Delhi court on Thursday denied Tyagi anticipatory bail before his surrender.Investigators said they will also get Tyagi’s phone forensically examined to ascertain the people he had contacted while trying to escape and also the communication between the two operators, besides details of the repairs. Police said Tyagi and Loveneesh had been running Hostel Daze from the Satya Niketan property since 2022.According to the FIR, the building owner and his brother had constructed four illegal floors on the nearly 50-year-old structure despite allegedly knowing that its foundation could not bear the additional load. Police said they will now cross-question all the accused.A labour contractor hired by building owner Mahesh Gupta told investigators that a plumber, who visited the spot around 90 minutes before the collapse, asked him not to break the wall. The contractor, identified as Sanoj Kumar, allegedly told the plumber that he had been instructed by his employer to carry out the work and would have to do it, another senior police officer, who did not wish to be named, said.The building collapsed after the wall was removed, trapping students and workers under the rubble. Five Delhi University students and two labourers were killed, six were injured, and 12 people were rescued in a 28-hour operation.Police said Loveneesh claimed that Tyagi and he had raised safety concerns about the construction work six to seven days before the collapse with Mahesh Gupta, but he reportedly told them that only minor work was being carried out.The two PG operators had also objected to plans for commercial activity on the ground floor, police said, but Gupta allegedly told them that he would speak to them later.Investigators have since also found that at least 20 other multi-storey buildings in Satya Niketan and nearby Moti Bagh appear require fire clearances, but never applied for one. Most function as student accommodations. Only three restaurants in the area were found to have fire clearances, HT reported on Friday.Under the Delhi Fire Service rules, buildings exceeding 17.5 metres in height, restaurants with seating capacity of more than 50 people and certain other commercial establishments are required to obtain fire clearances. Officials said many PGs and hostels operating from residential buildings do not obtain such clearances because they do not go through the licensing process followed by hotels and restaurants.