Complex sentence: On 14 Jan 1966, a tractor with a snowplough was clearing the landing strip of snow when it broke through the ice and sank to the bottom of the lake, taking the driver, Walter Wilde (29), with it.
Split into simpler sentences: On 14 Jan 1966, a tractor with a snowplough was used to keep the landing strip free of snow. One winter, however, the tractor broke through the ice and sank to the bottom of the lake, taking the driver, Walter Wilde (29), with it.