A heavily-pregnant teenager and her husband were killed after their car ploughed into a coach following a high-speed police pursuit. Newlyweds Patrick McDonagh, 19, and Shauna, 18, were tailed by at least nine police cars and a helicopter before the horror crash in west London on Sunday night. The pair were killed after their car smashed head on into a coach while driving on the wrong side of the A40 dual carriageway. Police had trailed the car for several miles towards central London after the three suspects fled the scene of an alleged aggravated burglary at an address in Harrow. Patrick McDonagh, 19, and Shauna, 18, (pictured together) were tailed by at least nine police cars and a helicopter before the horror crash in west London on Sunday night. The pair were killed after their car smashed head on into a coach while driving on the wrong side of the A40 A coach was also pictured with a large chunk missing from its front bumper following the crash The shattered wreckage of a Renault Megane people carrier was pictured in the middle of the A40 after the high-speed crash on Sunday night A police helicopter was called in to assist officers following the suspects, and reports on social media suggested as many as 10 police cars were involved in the chase. A third man was taken to hospital with serious injuries. The crash happened during a police chase after homeowners in Pinner, north west London, dialled 999 after being threatened by four men armed with a hunting knife and screwdriver. The four had broken into the home and for over 22 minutes threatened to kill two men, in their 30s and late 60s and a woman in her late 50s if they did not hand over their valuables. The younger man was punched in the face before the four fled with cash and jewellery. Within minutes officers were in pursuit. A Scotland Yard spokeswoman said the crash happened after police were called to the raid and chased the car with the help of the police helicopter. But she refused to say detectives were 'linking' the incidents as the Independent Office for Police Conduct had taken over the investigation into the crash while its officers are investigating the aggravated burglary. Police had trailed the car for several miles towards central London after the three suspects fled the scene of an alleged aggravated burglary at an address in Harrow Police were forced to screen the remains of one of the victims from public view after the deadly collision Asked if the burglary was linked with the fatal crash, she said: 'We are treating them as two separate incidents. 'The police (involved in the pursuit) had been responding to an aggravated burglary. That is the same as the incident (in Pinner). 'The IOPC is investigating the crash. We are not investigating both as a force can't investigate itself. We are not investigating the driving offences - the two occupants are dead. The third person was not the driver.' The spokeswoman said: 'Detectives are investigating after an aggravated burglary. 'The offence is believed to have happened between 8.15pm and 8.37pm on Sunday at a residential address in Pinner, Middlesex. 'The victims - a man in his mid-30s, a woman in her late 50s and a man in his late 60s - reported that the door to their home had been forced and four male suspects had entered the house. The Acton collision following a police chase happened at around 9pm last night on the A40 Westway, one of London's busiest roads 'The suspects then threatened the householders with a large hunting knife and screwdriver and demanded valuables. 'The victims were threatened they would be killed if they did not cooperate and one of the suspects punched the man in his 30s in the face causing swelling to his eye.' The shocked victims, who did not need hospital treatment, called the minute the raiders left and officers quickly gave chase to a fleeing car on to the A40. A police helicopter was scrambled to help with the chase but officers stopped following the car when it moved on the wrong side of the dual carriageway at about 9pm. Scotland Yard said: 'At approximately 8.40pm on Sunday police responded to a report of an aggravated burglary at a residential address in Harrow. 'As part of this response, a vehicle pursuit was initiated. The police helicopter was also called to assist. At approximately 9pm the vehicle being pursued moved onto the wrong side of the carriageway on the A40. The police vehicles did not follow. 'The vehicle was then in collision with a coach near the junction with Kingsdown Avenue. There were three occupants in the vehicle. Two people - one male and one female - were pronounced dead at the scene; a second male has been taken to hospital for treatment - condition awaits. 'No reports of any other serious injuries. 'The Directorate of Professional Standards and the Independent Office for Police Conduct have been informed.' All rights reserved for this news site dailymail and under his responsibility