A Google driverless car has been involved in a collision with a bus in California.
The tech company has admitted responsibility for the accident which occurred on 14 February.
It is thought to have happened while the company was testing 24 of the cars fitted with sensors and cameras near the tech firm's Silicon Valley headquarters.
In a report filed with California's Department of Motor Vehicles (DMV) the company reveals the car was trying to navigate its way round some sandbags at 2mph when it hit the bus that was travelling at 15mph.
Google says the accident came from the same kind of negotiations and misunderstandings that take place between human drivers every day.
The company says its cars will now have a better understanding that buses and other large vehicles are less likely to give way than smaller ones.
A DMV spokeswoman said the agency hoped to speak with Google soon about what went wrong.
Earlier this month, the Department of Transport revealed they were in "active discussions" with Google about trialling driverless cars in the UK.
In London, deputy mayor for transport Isabel Dedring said her office had spoken to Google "at least half a dozen times" over the past three years.
Google has admitted its driverless cars have been involved in 11 accidents - sparking new fears about the safety of autonomous automobiles.
"Over the 6 years since we started the project, we’ve been involved in 11 accidents
Google always blame crashes on other people, giving colourful descriptions of the other motorists on California's roads.
Google were asked how many of the 48 robotic cars were involved in crashes, but it has not yet replied.
This information is important because it could indicate wider problems with driverless machines.
If all the crashes happened to one car, it could be faulty.
If 11 separate motors were involved, this could potentially indicate a wider problem.