Possible Clues:

• Shallow crossing point in river
• 9 since died
• Supporting diamonds as bridge alternative
• Company that manufactures the starts of 20-, 32-, 41- and 52-Across
• Writer Ashley C. ___
• Eponym of the Detroit Lions field
• Creation of 16 across, cross monitor
• Harrison of ''Star Wars'' films
• See 6
• English writer makes US president (silly cow!) cross