The museum guard died of natural causes, too.
4 seconds sound clip from the The Mummy (1932) movie soundboard.
You can hear this line at 00:43:08.360 in the Blu-ray version of the movie.
Quote context
[...]
- Isis, the Egyptian symbol of life. I meant it for your father.
- What good could that old charm have done him?
- I tell you, the doctors say it's a plain case of heart failure.
- He's an old servant. He was frightened, but he'll be back.
- The museum guard died of natural causes, too.
- I saw your attraction to my patient last night, and hers to you.
- Hers to me? Do you really think so?
- But do you think I have a chance? 'Cause I think she's the most...
- But this is terrible at a time like this.
- I'm afraid. Will you go with me to her now?
- Yes.
- Then telephone her first not to leave the hotel.
[...]