So glad your babies are safe & that you heard the hawks before anything bad happened! It's a risky time right now for little fur butts.
Yes, reports of raptor numbers across the country indicate an increase this year for most species. Additionally, it's migration time, so more birds than usual are moving through most areas of the country for another few weeks. So you're more likely to have an encounter right about now.
Last night I had a pair of courting Great Horned Owls in my yard when i took Lexie out for her last pee. I literally stood right over her!