LOS ANGELES Frank Coghlan Jr., a silent-movie child actor who later played young Billy Batson, who transformed into Captain Marvel by uttering the magical word Shazam! in the landmark 1941 serial Adventures of Captain Marvel, has died. He was 93.

Coghlan died in his sleep Sept. 7 at his home in an assisted-living facility in Saugus, in north Los Angeles County, said his son Pat.

He was one of the busiest child actors of the late 20s and 1930s, said film critic and historian Leonard Maltin. He was a fresh, freckle-faced boy with great All-American-type appeal.

Maltin, who interviewed Cogh-lan numerous times in his later years and often saw him at nostalgia gatherings, said, He was just a sweet, sweet guy.

When I met him, said Maltin, he loved reminiscing, enjoyed meeting fans and was happy to be associated with what he knew was arguably the best serial ever made. His license plate said Shazam.

The 12-chapter Adventures of Captain Marvel serial from Republic Pictures marked the first time a comic book superhero was depicted on the big screen.

In Chapter 1, Batson is on an expedition to The Valley of the Tombs in Siam when a shaman gives him the ability to transform into Captain Marvel.

Coghlan was working on the 1941 MGM movie Men of Boys Town when his agent called to say Republic wanted to interview him for the role. I had no idea who Captain Marvel or Billy Batson were, Coghlan told Tom Weaver in an interview for Comics Scene magazine in 1994.

It was only after he was interviewed by the serials producer and two directors that he stopped at a drugstore and bought a copy of the comic book.

I said to myself, Hey, I do kind of look like that kid, he recalled.

Whenever Batson said Sha-zam! a giant flash and a cloud of white smoke appeared. And when the smoke cleared, Batson had become the mighty Captain Marvel (played by Tom Tyler).

Every time we did that, they ignited flash powder, which was in a trough in front of me, recalled Coghlan. And if the wind was unkind, Id get the powder flash in my face and lose some eyebrows.

Coghlan was born March 15, 1916, in New Haven, Conn. After his parents moved to Los Angeles, he began working in films as an extra when he was 3 years old.

Director Cecil B. DeMille, who signed Coghlan to a five-year contract, called him the perfect example of a homeless waif.