At least three persons were killed when the Howrah-Jagadalpur Samaleshwari Express' engine caught fire after the train rammed into a tower car engaged in repair work between Singapur Road and Keutguda in Odisha's Rayagada district on Tuesday, authorities said.The engine, luggage van and one general 2nd class coach of Samaleshwari Express derailed after hitting the tower car. While the engine caught fire following the incident, it has been detached, said an East Coast Railway (ECoR) official.Suresh, a technician of the maintenance tower car, Sagar, a senior section engineer (electrical) and Gouri Naidu, technician (electrical) of Rayagada, were killed in the accident.The incident took place at about 4.30 p.m. The coaches and passengers were not affected by the fire as only the engine was damaged in the incident, the ECoR said.Fire tenders doused the flames and an ambulance also reached the spot, officials said.The station masters on duty at Keutuguda and Singapur Road have been suspended, the ECoR said.The Railways have ordered an enquiry by the Commissioner of Railway Safety, Kolkata. Commissioner of Railway Safety is an independent statutory authority under the Ministry of Civil Aviation.A total of 148 passengers were on the train. They are being taken to Rayagada, said ECoR.