When a door broke loose on a new electric bus in Des Moines, Iowa, and nearly fell off, it was one in a long list of problems for the local transit agency. The city began using its fleet of seven electric buses, made by the startup Proterra, in 2021. The vehicles soon showed defects in the suspensions, weatherproofing, and wheelchair ramps. After only 18 months of use-and unsuccessful attempts to get the manufacturer to fix the problems-the agency had to pull them off the road.