What role, if any, the cracks played in the collapse has yet to be determined. “A crack in a bridge does not necessarily mean it’s unsafe,” said Robert Accetta, an official of the National Transportation Safety Board, which is investigating the accident, said at a news conference Friday night. The N.T.S.B. chairman, Robert Sumwalt, said the board has not yet determined on its own if there were cracks.

Construction crews were tightening cables on the bridge when it fell, the N.T.S.B. said, which is not unusual after installation. Mr. Accetta said the safety board also would look at whether that process contributed to the collapse, adding that the “point of failure” was still unclear.

But the possibility that cracks had occurred — and the question of when the bridge’s builders and designers, and school and state officials, had learned about them — was sure to become a focus of scrutiny and of finger-pointing.

Two days after the voice mail message was left, and one day before it was heard, the Florida Department of Transportation said, one of its consultants took part in a meeting with the bridge’s design and construction team. At the meeting the state consultant “was not notified of any life-safety issues, need for additional road closures or requests for any other assistance from FDOT,” the department said.

The meeting took place at noon on Thursday. At around 1:30 p.m., the bridge collapsed.

“At no point during any of the communications above did Figg or any member of the F.I.U. design-build team ever communicate a life-safety issue,” the state Transportation Department said in its statement.

But cracking in the structure was brought to the attention of representatives of the Florida Department of Transportation and the school just before the bridge collapsed, according to F.I.U. The school issued a statement early Saturday saying that during a meeting hours before the collapse, a Figg engineer “delivered a technical presentation regarding the crack and concluded that there were no safety concerns and the crack did not compromise the structural integrity of the bridge.”

The meeting, which took place at a trailer on the construction site Thursday morning, was convened by the builder and by Figg “to discuss a crack that appeared on the structure,” and representatives of both F.I.U. and the Florida Department of Transportation attended, the school said in its statement.