New Delhi, India (CNN) -- A pedestrian bridge under construction for next month's Commonwealth Games here collapsed Tuesday, officials said, adding to concerns raised about India's preparedness for the international sporting event.

At least 24 people were injured, three critically, said New Delhi police spokesman Rajan Bhagat.

The bridge near Jawarharlal Nehru Stadium came down while workers were laying a concrete slab, said Rakesh Mishra, engineer-in-chief for New Delhi's Public Works Department.

Designed as a pathway from a parking area to the stadium, the bridge was scheduled for completion this week. The games begin October 3.

"We are inquiring into it," said Mishra about the cause of the collapse. "It could be faulty execution or a fault in the design."

The games, hosted for the first time by the Commonwealth's most populous nation, have already been troubled by delays in construction projects and allegations of corruption.

Also Tuesday, Mike Hooper, chief executive officer of the Commonwealth Games Federation, complained of the conditions inside the rooms where the athletes are expected to live.

"Filth, excrement -- it really is disgusting in parts. And it really requires a professional, deep clean throughout the entire complex," he said.

Monsoon rains have similarly compounded the woes, with a spike in cases of dengue fever, water-logged streets and massive traffic snarls.

And this week, security concerns heightened after a shooting attack Sunday on a bus near a New Delhi mosque injured two Taiwanese tourists. Police, however, downplayed the assault as "local mischief," insisting the city is safe for visitors.