(Clarifies reference to 'managers' in headline)
MILAN, Sept 6 (Reuters) - Italian prosecutors have placed under investigation the top executives of Autostrade, the firm operating a bridge that collapsed last month killing 43 people, a judicial source said on Thursday.
The top managers of Autostrade, a unit of infrastructure group Atlantia, are among a list of 20 suspects which are being probed for alleged manslaughter, the source said. Autostrade was not immediately available for a comment. Prosecutors in Genoa are investigating the causes of the collapse of the Morandi bridge, which is part of the A10 motorway linking the northwestern Italian city to the French border.
A 200-metre section of the bridge gave way on Aug. 14, plunging dozens of vehicles into the valley below. (Reporting by Paola Balsomini, writing by Valentina Za, editing by Paola Arosio and Stephen Jewkes)