Freeway Hazard Sign Kills Man : Safety: Caltrans inspects message boards after wind topples one onto a pickup truck in Rancho Cucamonga.

Caltrans engineers were dispatched throughout Southern California on Tuesday to check the stability of freeway message signs after one toppled in strong winds Monday, instantly killing a motorist.

The five-ton electronic message board and supporting column fell during the evening rush hour, crushing the cab of a pickup and killing Donald Post, 52, as he was traveling south on Interstate 15 in Rancho Cucamonga.

Post, who lived near Lake Arrowhead, was driving home from his job as a maintenance engineer at Aerojet in Azusa.

The California Highway Patrol estimated that winds were gusting to 60 m.p.h. when the accident occurred. The sign’s message was warning at the time: “High Winds Ahead/Low Visibility.”

“The timing was unbelievable,” CHP Sgt. Mark Aldrich said. “The sign blew over just as he was passing beneath it. It was a real freak occurrence. I don’t know what the odds of that would be, but it must be up there with being struck by lightning.”

Caltrans had not yet determined what caused the 18-foot-high sign to fall, said Mike Miles, a division maintenance chief for Caltrans. The sign broke near its base, toppling the support standard and the 7-foot-by-25-foot message board that hung above the slow lane of traffic.

The victim’s family contended Tuesday that the 18-inch-diameter steel tubular support post had already sustained a stress crack, evidenced by rust, that caused it to snap in Monday’s high winds.

The family was seeking legal action to retain custody of the sign structure for private metallurgical analysis, said Bryan Hutchison, the fiance of Post’s eldest daughter, Tami.

He said he inspected the support post several hours after the accident and discovered rust along what he contended was a pre-existing crack.

“Right where it sheared, almost half of the shear already had rust and rust pitting on it,” he said. “You can tell it had a previous stress crack, and it was probably wobbling back and forth until it broke the rest of the way in the wind.”

Miles acknowledged Tuesday that he saw the same rust but said it was premature to speculate if there was a pre-existing stress crack.

“It’s a metal pole that is exposed to the elements. It could rust,” Miles said. “We have people coming from Sacramento who will take samples of the material, analyze it and determine what caused the failure.”

He said he did not know that the family was trying to keep the signpost for its own independent analysis. “Right now, the sign is ours,” he said.

But Hutchison said friends of his who are ironworkers have also inspected the sign standard and believe that it may have been improperly welded when it was installed.

“We want to oversee the analysis ourselves so there is no cover-up,” he said.

The other 20 electronic message signs in the Inland Empire were inspected Monday night and Tuesday and none showed any signs of structural weakness, Miles said. “This seems to be an isolated case,” he said.

However, two signs in areas prone to high winds were removed by Caltrans on Tuesday as a precaution. They are located along the northbound lanes of Interstate 15 at Sierra Avenue, across the freeway from the one that fell Monday night, and Interstate 215 at University Parkway in San Bernardino.

The signs are designed to handle sustained winds of up to 80 m.p.h. with gusts up to 104 m.p.h., Caltrans said.

The signs, which are programmed to warn motorists of weather and traffic conditions, are inspected during construction, installation and again every six years. The one that fell Monday was installed in June, 1994.

There are 228 electronic message signs statewide, Caltrans said.