SHERMAN OAKS (CBSLA) — Two construction workers were rushed to the hospital Tuesday afternoon after a shallow trench collapsed and trapped the men under a slab of concrete.

The contractor in charge of the work site, where the men were in the process of building a two-story addition to a home in the 5300 block of North Tyrone Avenue, said it happened in a split second.

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“It was a very poor built foundation,” Rogelio Ramirez, of Rojo Green Inc., said. “Whoever built that awhile back didn’t put any rebar on it, so what happened is a chunk of concrete just kind of fell on top of the guys.”

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The 911 call went out around 2:30 p.m. to report that the men were trapped. Ramirez said one man suffered broken ribs, while the other man is in critical condition.

“We just pray and hope these guys are OK,” Ramirez said. “That’s the main thing.”

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The battalion chief on the scene said there were no obvious signs of code violations and that the site appeared to be within safety parameters.