The National Highway Traffic Safety Administration has opened an investigation into Tesla’s Autopilot, the electric-car maker’s controversial driver-assistance software system. The probe comes after 11 crashes since 2018 in which the system was in use before Tesla vehicles struck vehicles at emergency scenes that included first responders. “Most incidents took place after dark and the crash scenes encountered included scene-control measures such as first-responder vehicle lights, flares, an illuminated arrow board, and road cones,” the agency said.

NHTSA’s Office of Defects Investigation will assess Tesla models between 2014 and 2021. Tesla was cleared in an investigation over a 2016 death involving the system, Yahoo News reports. Sen. Richard Blumenthal (D-CT) and Sen. Ed Markey (D-MA) have recently urged the NHTSA to investigate Autopilot, The Wall Street Journal reports.