Frohman made his annual trip to Europe in May 1915 to oversee his London and Paris "play markets", sailing on the Cunard Line's RMS Lusitania.
Songwriter Jerome Kern was meant to accompany him on the voyage, but overslept after being kept up late playing requests at a party.
William Gillette was also to have accompanied him, but was forced to fulfill a contracted appearance in Philadelphia.

Frohman's rheumatic knee, from a fall three years earlier, had been ailing for most of the voyage, but he was feeling better on the morning of May 7, a bright, sunny day.
He entertained guests in his suite and later at his table.
He was regaling them with tales of his life in the theater when, at 2:10 in the afternoon, within fourteen miles of the Old Head of Kinsale, with the coast of Ireland in sight, a torpedo from the German U-boat U-20 struck the Lusitania on the starboard side.
Within a minute, there was a second explosion, followed by several smaller ones.

As passengers began to panic, Frohman stood on the promenade deck, chatting with friends and smoking a cigar.
He calmly remarked, "This is going to be a close call."
 Frohman, with a disabled leg and walking with a cane, could not have jumped from the deck into a lifeboat, so he was trapped.
Instead, he and millionaire Alfred Vanderbilt tied lifejackets to "Moses baskets" containing infants who had been asleep in the nursery when the torpedo struck.
Frohman then went out onto the deck, where he was joined by actress Rita Jolivet, her brother-in-law George Vernon and Captain Alick Scott.
In the final moments, they clasped hands and Frohman paraphrased his greatest hit, Peter Pan: "Why fear death?
It is the most beautiful adventure that life gives us."
 Jolivet, the only survivor of Frohman's party, was standing with Frohman as the ship sank.
 She later said, "with a tremendous roar a great wave swept along the deck.
We were all divided in a moment, and I have not seen any of those brave men alive since."

Frohman died two months shy of his fifty-ninth birthday.
His body was later washed ashore below the Old Head of Kinsale, and it was later determined that he was killed by a heavy object falling on him, rather than by drowning.
His body lay among 147 others awaiting identification, where a rescued American identified him from newspaper photographs.
His body, alone among all the others, was not disfigured.
 His funeral service was held on May 25 at the Temple Emanu-El in New York City, and he was buried in the Union Field Cemetery in Ridgewood, Queens, New York.
Services were also arranged by some of his stars in other American cities: by Maude Adams in Los Angeles, by John Drew in San Francisco, by Billie Burke in Tacoma, and by Donald Brian, Joseph Cawthorn and Julia Sanderson in Providence, as well as memorial services at both St Paul's Cathedral and the Church of St Martin-in-the-Fields in London.
Frohman was also eulogized by the French Academy of Authors in Paris.

A memorial to Frohman is located on The Causeway at Marlow on Thames.
The site features a fountain with a sculptured nymph and inscription.
Frohman made his annual trip to Europe in May 1915 to oversee his London and Paris "play markets", sailing on the Cunard Line's RMS Lusitania. Songwriter Jerome Kern was meant to accompany him on the voyage, but overslept after being kept up late playing requests at a party. William Gillette was also to have accompanied him, but was forced to fulfill a contracted appearance in Philadelphia.
Frohman's rheumatic knee, from a fall three years earlier, had been ailing for most of the voyage, but he was feeling better on the morning of May 7, a bright, sunny day. He entertained guests in his suite and later at his table. He was regaling them with tales of his life in the theater when, at 2:10 in the afternoon, within fourteen miles of the Old Head of Kinsale, with the coast of Ireland in sight, a torpedo from the German U-boat U-20 struck the Lusitania on the starboard side. Within a minute, there was a second explosion, followed by several smaller ones.
As passengers began to panic, Frohman stood on the promenade deck, chatting with friends and smoking a cigar. He calmly remarked, "This is going to be a close call."  Frohman, with a disabled leg and walking with a cane, could not have jumped from the deck into a lifeboat, so he was trapped. Instead, he and millionaire Alfred Vanderbilt tied lifejackets to "Moses baskets" containing infants who had been asleep in the nursery when the torpedo struck. Frohman then went out onto the deck, where he was joined by actress Rita Jolivet, her brother-in-law George Vernon and Captain Alick Scott. In the final moments, they clasped hands and Frohman paraphrased his greatest hit, Peter Pan: "Why fear death? It is the most beautiful adventure that life gives us."  Jolivet, the only survivor of Frohman's party, was standing with Frohman as the ship sank.  She later said, "with a tremendous roar a great wave swept along the deck. We were all divided in a moment, and I have not seen any of those brave men alive since."
Frohman died two months shy of his fifty-ninth birthday. His body was later washed ashore below the Old Head of Kinsale, and it was later determined that he was killed by a heavy object falling on him, rather than by drowning. His body lay among 147 others awaiting identification, where a rescued American identified him from newspaper photographs. His body, alone among all the others, was not disfigured.  His funeral service was held on May 25 at the Temple Emanu-El in New York City, and he was buried in the Union Field Cemetery in Ridgewood, Queens, New York. Services were also arranged by some of his stars in other American cities: by Maude Adams in Los Angeles, by John Drew in San Francisco, by Billie Burke in Tacoma, and by Donald Brian, Joseph Cawthorn and Julia Sanderson in Providence, as well as memorial services at both St Paul's Cathedral and the Church of St Martin-in-the-Fields in London. Frohman was also eulogized by the French Academy of Authors in Paris.
A memorial to Frohman is located on The Causeway at Marlow on Thames. The site features a fountain with a sculptured nymph and inscription.
Charles Frohman