Murray & Roberts Holdings Ltd. has hired independent consultants to help investigate the collapse of the support structure of a bridge being built over a Johannesburg freeway that killed two people and injured several others.

The shares of South Africa’s second-largest construction company gained 4.8 percent to 11.69 rand at 10:17 a.m. local time, part reversing a 7.3 percent fall after the company confirmed it was responsible for construction on Wednesday.

It’s too early to speculate about the cause of the accident, Murray & Roberts Chief Executive Officer Henry Laas said by phone on Thursday.

“It is in everybody’s interest to get to the root cause of this incident as quickly as possible so that we know what went wrong here and that we can prevent something like this from ever happening again,” Laas said. “It is going to take time, we don’t want to jump to a conclusion but we want to get answers as soon as possible.”

The freeway, which feeds Johannesburg’s financial district, remained closed on Thursday morning while the clearing operation continued.

The Department of Labor will conduct a separate investigation on behalf of the authorities, Laas said. Murray & Roberts was informed that a third person had died, he said.

Transport Minister Dipuo Peters has called on authorities to conduct a thorough investigation into the incident, the government department said in a statement.

The bridge was being built for pedestrians walking to the financial district of Sandton from the nearby Alexandra township, it said.

The steel support structure which collapsed had been assembled off site in four main pieces, Laas said.

The construction had only recently been completed when the collapse occurred. The investigations could take months, although “hopefully not that long,” he said.

–Bloomberg (Liezel Hill)