How Do You Crash A Bus On A Straight Motorway?

[ToraToraTora]

https://www.bbc.co.uk/news/uk-england-merseyside-66970993

I reckon the driver either fell asleep or was playing on his phone or somwthing.

[nicebloke1]

And neither did the link indicate that the driver had, or may have committed any serious traffic offence that may have caused the deaths. There is a high and low level of speculation, speculation on this level is what the police wanted to avoid for those involved.

[THECORBYLOON]

It was speculation as the link at the time of the OP had no reference to a medical issue.

 

The cause of the crash is unknown still.

[Paul22118]

The jungle drums say 'cardiac issue'........

[pastafreak]

23:14...I read the link 10 minutes after it was posted here. A"medical issue" was mentioned...and had already been referred to in other media sources.

[ABSpareEditor]

A quote from the police, as stated in the article sourced: 

"We would also ask the public to avoid speculating on the incident or posting information or images which could be distressing for the families and those involved."