"Big" Ron O'Brien, afternoon jock on 98.1 WOGL, died yesterday from complications of pneumonia, station manager Jim Loftus confirmed last night.

O'Brien, who was 56 and lived in King of Prussia, had been off air recently and hospitalized at Paoli Memorial Hospital. He had recently shown signs of improvement and had come out of intensive care, Loftus said, adding that he and the rest of the WOGL team were planning to visit him this week and were shocked by his death yesterday.

"He was one of the true best," said Loftus, who first heard O'Brien's work on a nationally syndicated show called "On the Radio." "It's easy to say that about someone who died, but in his case, it's absolutely true.

"The interesting thing was he was a Boss jock from the glory days who kept that same style but also evolved through contemporary times. That was his gift. He could talk up and introduce the same song for the 4,000th time but each time he could convey excitement," said Loftus, whose station will soon present audio and video retrospectives of O'Brien's work.

"He was a model employee and a wonderful talent," Loftus said of O'Brien, who had recently signed a three-year contract extension with the radio station.

O'Brien was on WFIL from 1976 to 1979. His career also took him to New York's WNBC, where he made a lasting impression on a young Howard Stern. The shock jock praised O'Brien in August 2006, talking about how the DJ was a true professional who had covered a few of Stern's shifts for him.

O'Brien had worked at WOGL, which plays hits of the 1960s and '70s, since 2002. "He made every afternoon ride home fun for the thousands who listened," Bob Kelly, traffic anchor at WOGL and CBS 3, said last night.

"A great voice, classic Boss Jock delivery and a great sense of humor," says Kelly, noting that his friend and colleague also "loved trolleys." Although he didn't ride them, he enjoyed watching them and "always complained when the Route 15 was using shuttle buses. Philly radio has lost a legend," Kelly said last night.

O'Brien's radio career began at Kansas City's KUDL in 1969, according to a 2006 biography by the Broadcast Pioneers of Philadelphia. He also worked at KTLK in Denver, WQXI in Atlanta, WCFL in Chicago, WXLO in New York and WOKY in Milwaukee. O'Brien worked in Los Angeles at KFI and KIIS before moving to KWK in St. Louis in 1985. He stayed for nine years, until his return to Denver at KZDG.

He returned to Philadelphia in 1996, when he joined Star 104.5, which later became Alice 104.5.

Word of O'Brien's death spread on the Internet. "Ron, you will be missed. You made me want to be in radio after listening to you in Atlanta back in 1972. . . . I was listening to you each and every night while doing my homework," wrote "Glowing Tube" in the comment section of Reelradio.com, an online Top 40 radio archive that includes several recordings of O'Brien's work, though none from Philadelphia.

"He worked at many radio stations in the days when you went from market to market and just kept going. . . . R.I.P. Ron O'Brien. You always will be fondly remembered by all of us," Larry Stoler posted on Reelradio.com.

"I stopped to visit at WOGL two years ago and to swap a few stories; just the nicest most gracious radio legend I've ever met," Kevin Fitzgerald posted on the Philadelphia board of radio-info.com.

Funeral arrangements are pending, but Loftus said a service, open to O'Brien's fans, is likely to be held Friday. The DJ is survived by his mother. *

Staff writer Kevin Bevan contributed to this report.