Four Egged workers were questioned under caution by Israel Police on Tuesday following accusations of negligence that lead to the serious Route 1 crash that killed six people on February 14.Egged’s Jerusalem-region manager, its human resources manager, an employee in its insurance department and a safety officer for the district are being investigated.Its national safety officer was also being questioned, though not under caution, and police are expected to question further officials in the coming days.According to police, Haim Biton was driving his No. 402 Egged bus on Route 1 from Jerusalem to Bnei Brak, when he allegedly “left the right lane and began driving on the shoulder and did not notice a disabled truck on the side of the road and struck it with great force.”Almost all the passengers sitting on the right side of the bus were killed or injured as a crane mounted on the back of the truck gutted the side of the bus. Immediately following the crash, Biton allegedly tampered with the tachograph, which records the vehicle’s speeds and distances covered over a 24-hour period.During a Jerusalem Magistrate’s Court hearing last month, officer Moshe Cohen said that Biton was using his cell phone while driving the No. 402 bus that night.It was revealed in court that Biton was involved in an earlier accident in December 2013, in which 18 people were injured after his bus hit a truck ahead of him. The crash occurred while he drove the same No. 402 bus line, not far from the location of the February incident.Biton was permitted to return to work following the 2013 crash, but was reportedly forbidden from driving intercity bus lines. However, several weeks before this most recent accident, Egged allowed him to resume driving intercity lines.