A small hatchback was crushed by a lorry in a four-vehicle pile-up, which also involved a Mercedes saloon and a double-decker bus, along Ang Mo Kio Ave 5 on Saturday afternoon.
The male driver of the hatchback was trapped in his car and had to be extracted by Singapore Civil Defence Force (SCDF) officers with heavy appliances.
An SCDF spokesman said the driver was conscious when conveyed by ambulance to Tan Tock Seng Hospital where he was found to have suffered mulitple injuries.
The female driver of the bus was also sent to hospital after she complained of pain in her stomach and right knee.
The accident took place just before the traffic light junction of Ang Mo Kio Ave 5 and Serangoon Ave 6.
The police said they received a call about the accident at about 1.55pm. Investigations are ongoing.