Federal wildlife investigators who visited the BrightSource Energy plant last year and watched as birds burned and fell, reporting an average of one “streamer” every two minutes, are urging California officials to halt the operator’s application to build a still-bigger version.

The investigators want the halt until the full extent of the deaths can be assessed. Estimates per year now range from a low of about a thousand by BrightSource to 28,000 by an expert for the Center for Biological Diversity environmental group. MORE