Just days before a self-driving Uber vehicle killed a pedestrian earlier this year in Tempe, Ariz., a manager in the ride-sharing company’s autonomous vehicle division sent executives an 890-word email warning of safety concerns, TechCrunch reported. The email was sent to the division’s head, along with other top executives and lawyers. The warning was made public by The Information, which verified the claims after speaking with current and former Uber employees. Robbie Miller, who was an operations manager for the unit’s testing operations at the time, wrote in his email the unit needed to “work on establishing a culture rooted in safety.” Miller warned that “cars are routinely in accidents resulting in damage” and added that backup drivers, who sit behind the wheel in case of an emergency, were not properly trained to handle the vehicles when there were safety issues. According to Miller, “a car was damaged nearly every other day in February” and was “usually the result of poor behavior of the operator or the AV technology.” He also said repeated infractions would rarely result in terminating backup drivers, several of whom “appear to not have been properly vetted or trained.” Just five days after Miller alerted executives to these safety concerns, an autonomous car operated by Uber that also had a backup driver, killed a woman while the company was testing the program in Arizona, the New York Times reported. Following the incident, Uber suspended its driverless car testing operations in Tempe and Pittsburgh. The Information reported Miller’s concerns were discussed during an Uber internal safety review following the fatal accident, according to sources they interviewed. In a statement provided to Fortune, an Uber spokesperson said, “Right now the entire team is focused on safely and responsibly returning to the road in self-driving mode. We have every confidence in the work that the team is doing to get us there.” “Our team remains committed to implementing key safety improvements, and we intend to resume on-the-road self-driving testing only when these improvements have been implemented and we have received authorization from the Pennsylvania Department of Transportation.” Uber says the information included in the email to the autonomous vehicle division was also included in an internal safety review.