At the height of the morning peak hours, a portion of the Gokhale Bridge, running east-west over the Andheri station, suddenly came down trapping at least five persons, and paralysing the suburban and long-distance train services on the WR.

Coming nine months after the Elphinstone Road FOB crash and stampede that left 23 commuters dead, Tuesday's incident instilled fear among the commuters, especially since at least three jam-packed locals had passed seconds before the bridge caved in on the railway tracks.

Coupled with torrential overnight rains, the crash severely hit Mumbai's lifeline -- the suburban train services which ferry around eight million commuters daily.

Many parts of the city and suburbs including Kandivali, Jogeshwari, Andheri, Kurla, Santacruz, Chembur, Tilak Nagar and surroundings experienced flooding or waterlogging.

The injured are admitted to the Brihanmumbai Municipal Corporation's R.N. Cooper Hospital in Vile Parle, a BMC official said. One of them, a woman, was critical.

Railways Minister Piyush Goyal who has ordered an inquiry into the incident is likely to visit the crash site later this evening, said officials.

Work was taken up on a war footing to clear the debris from the tracks which blocked services in both directions, and repair the overhead high-tension power lines and tracks, the platform roof and other equipment that was broken or damaged.

According to WR spokesperson C.N.K. David, the bridge portion crashed at 7.37 a.m. on the southern-end of the Andheri platform numbers 7-8.

"The restoration work is in full swing and we hope to resume normal train services in the next few hours," David said.

The local trains were being operated between Goregaon-Virar on the northern side and Bandra-Churchgate in the southern direction, besides Harbour Line from Bandra-CST, and several long-distance trains were cancelled or terminated at various locations or rescheduled.

The Commissioner of Railway Safety will investigate the incident which has triggered a blame-game between the WR and the BMC.

While the WR said the bridge belongs to the BMC, the latter said the crash took place on the railway portion which was the WR's responsibility for repairs and maintenance.

With several lakhs of commuters stranded all over the network, many walking down on the railway tracks to the nearest station, civic transport body BEST deployed 40 additional bus services between Goregaon and Bandra to clear the rush.

The cascading effect was also seen on the Western Express Highway, the main S.V. Road, Link Road and other arterial roads with traffic jams all over.

The roof of a BEST double decker bus was partly sliced off when it hit an overhead obstacle near Vakola, further adding to the traffic chaos.

Stuck at various points on the suburban network, Mumbai's famed Dabbawalas suspended all their tiffin box deliveries on Tuesday on the WR routes but would continue on other routes, said spokesperson Subash Talekar.

As a precautionary measure, Mumbai police stopped all traffic above and below the Gokhale Bridge till the green signal from WR authorities.

The Opposition Congress and Nationalist Congress Party sharply criticized the ruling Bharatiya Janata Party-Shiv Sena for the Mumbai mess - second time since the June 9 downpour - and demanded stringent action against those responsible for it.