A Royal Mail lorry driver who nodded off at the wheel and killed a grandfather-of-six on the M271 was playing Romanian shows on his phone, a court heard.

But Stefan-Alexandru Bloj told jurors he was just listening to them and not watching the screen.

His 44-tonne HGV ploughed into the back of David Sullivan's Citroen at just under 40mph as he approached Redbridge roundabout.

Witnesses who saw the horror smash compared it to an 'explosion' and said it had a 'domino effect', causing injuries to drivers in two cars in front of Mr Sullivan's white Citroen Relay van.

After being hit by Bloj's Mercedes Actros lorry, Mr Sullivan died from devastating injuries.

READ MORE: Tributes for 'beloved' man who died in M271 crash

Since the accident at around 8.30am on November 17, 2020, the 34-year-old told Southampton Crown Court he has been diagnosed with obstructive sleep apnoea.

Bloj - who was on his first ever night shift for Royal Mail - also revealed he only had three hours sleep before the shift which lasted over 14 hours.

Jurors heard Romanian Bloj wasted his rest breaks to watch videos on his phone and text his partner.

Daily Echo: Stefan-Alexandru Bloj outside Southampton Crown CourtStefan-Alexandru Bloj outside Southampton Crown Court (Image: Solent News and Photo Agency)

Mr Sullivan, 64, slowed down to approach Redbridge roundabout at the end of the M271 when Bloj's lorry crashed into the back of him.

Giving evidence at Southampton Crown Court, Bloj said at the time he thought he was fit to drive and he 'had no problems with sleep before the collision'.

However, he said he was diagnosed with 'severe' sleep apnoea - when your breathing stops and starts while you sleep, causing sleepiness in the day - following a trip to his home country of Romania after the crash.

He told the court: "I was in a big depression for a couple of months.

"I flew back to Romania to have the support of my family back there.

"They noticed that I was snoring loudly when I was sleeping so that was a concern.

"I came back to the UK to the UK and I went to see my GP."

Daily Echo: Stefan-Alexandru Bloj denies causing death by dangerous drivingStefan-Alexandru Bloj denies causing death by dangerous driving (Image: Solent News and Photo Agency)

Before the crash, Bloj had slept for just three hours - with half an hour being in the previous morning and two and a half hours being a short sleep before work.

He told the court, however, that with this amount of sleep, he still felt okay to drive and denied feeling tired the day before.

Bloj said he cannot recall the events, adding: "I had to open the seat belt and get out.

"I was in shock and I didn't understand what happened.

"It made me feel very, very bad and shocked, I went to go and see what happened.

"I feel deeply bad about what happened to him [Mr Sullivan] and feel bad for his family also and I assure them that this will stay with me for life."

Prosecutor Tana Adkin KC told the court Bloj would have likely been suffering the condition at the time of the accident but had failed to recognise symptoms.

The day of the crash, a last minute change to the schedule meant Bloj was working longer than he intended to, it was heard.

He was concerned about this change as the maximum shift that can be worked by an HGV driver is 15 hours, and this delivery may exceed his working time.

Bloj said: "It was a problem to me because I was concerned there would not be enough time to go back to Eastleigh (the collection site) and unload, and then go back to Marchwood (the vehicle operation centre).

"Before taking the load, I called my supervisor and informed him about what the other supervisor is asking me to do and I expressed my concern."

Bloj denies causing death by dangerous driving.

The trial continues.