“The point was that men on both sides of Artie's family had a tendency to keel over before they got old.”
“Several looked like they were ready to keel over and perform an Olympic face-plant.”
“Dearest," he said, "don't slip that on your finger; put your arms around my neck and promise me, all at once and abruptly, or I'll keel over and die of sheer joy.”
“‘If I came up in that wretched glass box of yours without turning a hair, I’m hardly going to keel over now!”
Mistress for a Weekend
“We don't," Carson said, glaring at Bult's pony, which looked like it was getting ready to keel over again.”
“Reverend Teaks would lay his hands on someone in the crowd to heal them and they would keel over with a heart attack instead.”
These user-created lists contain the word ‘keel over’.
Arguably, a nightmare for non-native speakers of English
Looking for tweets for keel over.