Defenders UK - Season 5 Episode 3 -

DVSA inspectors investigate the cause of a horrific crash in which an HGV careered out of control, smashing through a motorway central reservation and killing two people. The HGV is found to have a defective braking system and is one of a fleet of vehicles operated by a company putting profits before safety. The haulage company's boss faces the prospect of jail after the inspectors discover he ignored warnings about the defective brakes.