A heavily-pregnant teenager and her husband who were killed in a high-speed police pursuit. Newlyweds Patrick and Shauna McDonagh - who were expecting their first child together - were tailed by at least nine police cars and a helicopter before the horror crash in west London on Sunday night. The couple were thought to have been suspects in an aggravated burglary that took place north of the capital in Pinner, Harrow, a short time earlier. But the Independent Office for Police Conduct (IOPC) today confirmed the couple were not present at the time of the aggravated burglary that prompted the officers' response. Scroll down for video 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 Mr McDonagh, 19, and his wife, 18, who got married just 11 weeks ago, were pronounced dead at the scene after their car smashed head on into a coach while they were driving on the wrong side of the A40 dual carriageway. Their unborn baby girl, who was due in April, is not believed to have survived the crash. A third person in the car was taken to hospital and has since been arrested on suspicion of aggravated burglary. Patrick and Shauna McDonagh (pictured) were pronounced dead at the scene Three victims - a man in his 30s, a woman in her late 50s and a man in his late 60s - were threatened with a 'large hunting knife' and screwdriver after being confronted by four men during a raid in north London. The younger victim was punched in the face before the thieves fled the scene with cash and jewellery. In a statement today the IOPC said the couple were driving on the wrong side of the road. The statement said the crash took place on the A40 in East Acton, west London around 9pm Sunday 10 February. The IOPC added: 'Shauna McDonagh aged 18 who was pregnant and Patrick McDonagh, aged 19, were pronounced dead at the scene. 'A second man who was travelling in the car was taken to hospital. A large number of people travelling on the coach were checked by paramedics at the scene with two taken to hospital with minor injuries. It is understood that police were pursuing the car, a Renault Scenic, for about 10 minutes but terminated the pursuit prior to the crash. A National Police Air Service helicopter was monitoring the progress of the Renault when it crashed. 'It has now been confirmed, as part of a separate police investigation, that the occupants of the Renault were not present at the time of an aggravated burglary reported to have taken place in Harrow.' The IOPC investigation will now examine the information the police had and the rationale for the pursuit. IOPC regional director Jonathan Green said: 'My thoughts are with the families and friends of Patrick and Shauna, those injured and all those affected by this incident. 'It is important that we now establish all of the circumstances surrounding this collision. 'We have therefore launched an independent investigation into the events leading to the collision and immediately deployed our investigators to attend the scene and the post incident procedure.' The crash happened during a police chase after the homeowners dialled 999. Police were forced to screen the remains of one of the victims from public view after the deadly collision The pair got married 11 weeks ago and we preparing for their first child together 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. 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. Mr McDonagh and his wife Shauna (pictured left and right), 18, who got married just 11 weeks ago, were pronounced dead at the scene after their car smashed head on into a coach '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. Patrick McDonagh shared his excitement about him and his wife expecting a girl on Facebook The Acton collision following a police chase happened at around 9pm last night on the A40 Westway, one of London's busiest roads '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