One Home guard waskilled and another was injured when a speeding truck hit their motorcycle in East Champaran district on Wednesday night, police said.Deputy Superintendent of Police Jyoti Prakash said the mishap took place around 8 pm in Paharpur police station area of East Champaran when Om Prakash Pandey (31) and Prem Bhushan Tiwari (52) were on their way to the adjoining West Champaran district.Pandey died on the spot while Tiwari received serious injuries and he was rushed to a hospital by police personnel where his condition was stated to be critical, the DSP said.He said both were residents of Bettiah, the district headquarters of West Champaran and were returning from Patna where they had been deployed for traffic control.A search was on for the truck that knocked them down and the errant driver, the DSP added.