Bengaluru, Aug 30 : A day after three workers were killed in a firecracker warehouse fire in Karnataka's Haveri district, police on Wednesday arrested the owner of the unit. Another person succumbed to his burn injuries this morning taking the death toll to four. Expressing grief over the tragedy, former chief minister Basavaraj Bommai demanded an investigation into the incident. 'The incident of four workers being charred to death in a firecracker warehouse fire incident is unfortunate. The state government should investigate the matter and provide suitable compensation to victims,' he stated. The officers should focus on workers who work in hazardous places and ensure preventive measures. The safety of labourers must be ensured, the former chief minister said. He also announced Rs 1 lakh compensation from the BJP party for the families of the deceased. While bodies of Dyamanna Valikara (28), Ramesh Barki (26), Shivalinga Akki (26) were recovered on Tuesday, Jayanna was found dead this morning. All the workers hailed from Katenahalli village and were charred to death. The police have arrested Kumara Sathenahalli, the owner of the warehouse in connection with the incident. The Fire Force and Emergency services personnel carried out an operation for 16 hours and extinguished the fire in the wee hours of Wednesday. Crackers worth in crores were stored at the warehouse to be sold during the Ganesha festival. Authorities suspect that welding work on the premises of the warehouse triggered the fire. One Wasim Harihar (32) was seriously injured as he jumped off the building. Chief Minister Siddaramaiah had announced Rs 5 lakh compensation for the families of the deceased. /IANS