At least 22 people died and more than 30 others suffered injuries in a stampede at Mumbai’s Elphinstone railway station on Friday.

The stampede was triggered when people rushed through a narrow foot-over bridge connecting Elphinstone and Parel train stations, following heavy rain.

Images of the tragedy circulating online showed piles of people gushing through the iron grills of the dilapidated bridge and its staircase.

According to a report, the stampede broke out at about 10:30 am near a ticket window on the bridge. Railway spokesperson Anil Saxena told NDTV, “Many were waiting in the rain. There were too many people in a cramped space. When people were trying to rush to their trains, the stampede happened.”

Hours after the incident, authorities remained clueless about what triggered the stampede. Reports quoted several witnesses citing various reasons for the stampede. In one report, India TV, said a rumour of the overbridge collapsing led to panic among people, and in another cited a witness saying that a rumour of a suspected electrical short-circuit sparked off a panic run.

Western Railway PRO Gajanan Mahatpurkar, meanwhile, confirmed the death toll, and all the victims were taken to KEM Hospital. The hospital too confirmed 55 casualties and released the names of victims. Thirteen men, eight women and one child lost their lives in the accident. 24 men and nine women were among the 33 injured. “Of the injured, 20 people have serious injuries, rest have minor injuries,” GRP Commissioner Niket Kaushik told reporters.

Identities of a majority of the deceased are yet to be ascertained.

Union railway minister Piyush Goyal, who visited the spot, ordered an inquiry headed by the Chief Safety Officer of the Western Railway. Maharashtra Chief Minister Devendra Fadnavis also said an “inquiry will be conducted by the Government of Maharashtra and Ministry of Railways and necessary-strict action will be taken.” Fadnavis also announced a ₹5 lakh compensation for the next of the kins of deceased and said, “all the medical expenses of the injured will be borne by GoM.”

The incident has triggered an outcry, since locals had been warning officials about the threats presented by the narrow bridge. A year ago, a Twitter user Chandan KK sent out a tweet-warning to the then Railway minister Suresh Prabhu that such a tragedy was waiting to happen.

More recently — just two days ago — Mumbai journalist Santosh Andhale had tweeted to Railway Minister Piyush Goyal and Western Railways about the bridge.

A regular local train user told Asia Times, “Several such stations in Mumbai, including those in Dadar and Kurla, face such threats. During peak hours, we see massive rushes and overcrowding.”

Mukul Jain, Divisional Railway Manager of the Mumbai Central Unit of the Western Railway, however, defended the bridge and blamed the accident on rain and rush.

As per 2016-17 estimates, Mumbai operates over 2000 local train services that cater to over seven million daily users, making it one of the busiest and over crowded commuter railway systems in the world.