Firefighters were called to Bedfont Road just after midnight to reports of a collision between a car and bus which then caught fire.
The H26 service was heading towards Hatton Cross when it collided with a Mercedes on a railway bridge.
Three people were declared dead at the scene and six others were taken to hospital.
The H26 works on the Hounslow/Feltham/Heathrow loop and Bedfont Road has been closed since the collision happened (correct as of 3pm). Stay tuned to 107.8 Radio Jackie for the latest traffic news.
Video: UKNIP
