I'm afraid the strain was more than he could bear.
5 seconds sound clip from the Tombstone (1993) movie soundboard.
You can hear this line at 01:51:43 in the Blu-ray version of the movie.
Quote context
[...]
- All right, lunger. Let's do it.
- Come on. Come on! Oh, Johnny. Come on!
- You're no daisy. You're no daisy at all!
- Poor soul. You were just too high-strung.
- I'm afraid the strain was more than he could bear.
- Oh, I wasn't quite as sick as I made out.
- My hypocrisy goes only so far.
- Indeed, sir. The last charge of Wyatt Earp and his immortals.
[...]