Between October 21 and 22, 2025, during excavation work for water pipe installation on the sidewalk of National Route 299 in Chichibu City, Saitama Prefecture, Saitō-gumi Corporation damaged NTT's underground pipes and communication cables. This resulted in communication failures affecting ATMs, telephones, and internet lines in the vicinity. Full temporary recovery of all lines was completed around 00:10 on October 23, 2025. This incident falls under Article 28, Paragraph 1, Item 1 of the Construction Business Act. The company holds a general construction license (Permit No. 1284) issued by the Saitama Prefectural Governor. The prefecture issued an instruction requiring the company to ensure proper construction practices, promptly inform staff of the incident, develop and implement training plans to prevent recurrence, and submit a written report within three weeks.