Kolkata: At least 21 people were killed and 88 injured and some others feared trapped as a portion of an under-construction flyover collapsed on a congested road intersection here on Thursday, crushing people and vehicles as the state government ordered a high-level probe into the incident.

Kolkata flyover collapse helpline - 1070

Events as they unfolded:

- PM Modi calls WB CM Mamata Banerjee, expresses condolences for the bridge collapse incident, offers all assistance.

PM spoke to WB CM @MamataOfficial on the situation arising due to the collapse of an under construction flyover in Kolkata. — PMO India (@PMOIndia) March 31, 2016

PM expressed grief on the mishap in Kolkata & assured all possible support from the Centre. — PMO India (@PMOIndia) March 31, 2016

- As of now 21 are dead, 85 injured out of which 2 are very serious: WB CM.

- 3 more NDRF teams sent to Kolkata bridge collapse spot keeping in view the prolonged rescue ops. 10 teams with 400 rescuers on spot now.

- In view of the tragic flyover collapse, Facebook has activated its safety check feature for people in Kolkata which will allow its users to mark themselves 'safe' - PTI.

- Kolkata Police Commissioner Rajeev Kumar informs that 3 offices of IVRCL were raided but no one was found there: Report.

- 6-member fact finding committee formed to look into the incident.

- 3 FIRs registered against the IVRCL infrastructure company including at Jorasanko Police Station.

- At least 18 people are reported killed as of now.

- CBI registers case against 4 persons and a company from Kolkata for allegedly cheating SBI of Rs 34.46 crore in name of loan. Further investigation is on.

- 5 NDRF teams are working with 268 personnel, they are trying to locate trapped victims. OP Singh, DG, NDRF.

- Manohar Parrikar expresses shock and grief over loss of life in Kolkata flyover collapse, instructs Armed Forces to provide all necessary support.

- PM called me up and I apprised him of the rescue operations being carried out by the NDRF in Kolkata. We'll provide maximum assistance possible: Rajnath Singh.

- 45% work was left, one girder missed and second one fell. It is nothing but God's act. This has never happened before, we are also in shock. KP Rao, IVRCL Infrastructure company on Kolkata bridge.

- Army sends 6 more ambulances at the spot. 5 army columns deployed at the accident site.

- Toll rises to 17: Reports.

- PM Narendra Modi expresses shock over collapse of flyover in Kolkata, says he took stock of the situation and rescue operations.

Shocked & saddened by collapse of under construction flyover in Kolkata. Took stock of the situation & rescue operations. — Narendra Modi (@narendramodi) March 31, 2016

My thoughts are with the families of those who lost their lives in Kolkata. May the injured recover at the earliest. — Narendra Modi (@narendramodi) March 31, 2016

- ANI reports that employees of infrastructure company IVRCL, which had contract for the collapsed Kolkata flyover, left their Hyderabad office Hyderabad after the incident happened

- CM Mamata Banerjee has announced a compensation of Rs 5 lakh to the families of the dead and Rs 2 lakh each for those critically injured as well as Rs 1 lakh for those who suffered minor injuries.

WB CM Mamata Banerjee at the spot where under-construction bridge collapsed near Ganesh Talkies in Kolkata. pic.twitter.com/1TBrjKuWjP — ANI (@ANI_news) March 31, 2016

- Kolkata Police confirms 14 people dead and 78 injured in the under-construction flyover collapse incident near Ganesh Talkies

- A helpline number has been issued for Kolkata flyover collapse - 1070

- The number of injured is currently being reported at over 100

- IANS reports that at least 10-12 people were rushed from the debris to the Calcutta Medical College and Hospital

- MoS Home Kiren Rijiju says the Centre will send more NDRF teams and paramilitary forces if necessary

- Reports say a bus, possibly a mini-bus, is also trapped under the debris of the collapsed bridge

- CM Mamata Banerjee describes the bridge collapse as "a very unfortunate incident"

- One Engineer team of the Army has also reached the spot with specialist equipment

- Army has already deployed 4 columns of rescue personnel. There are 3 medical teams. Two ambulances, surgeons and nursing assistants in each team, reports ANI

- We don't have the death toll or information on how many are injured. 100 metres of the bridge have collapsed - OP Singh

- More teams are being mobilised for accident spot in Kolkata, two teams have already reached there, says OP Singh, DG, NDRF

- Chief Minister Mamata Banerjee has reached the spot of the bridge collapse to take stock of the situation first hand

- Army has been called in to assist in rescue work at the bridge collapse site. Troops are on their way.

Car being pulled out from the debris of the collapsed bridge near Ganesh Talkies in #Kolkata pic.twitter.com/o3Zx4uvXKd — ANI (@ANI_news) March 31, 2016

- Home Minister Rajnath Singh speaks to DG, NDRF, says rescue teams have been rushed to the spot

Deeply saddened to know that precious lives have been lost in the Kolkata accident.My heartfelt condolences to the families of the deceased — Rajnath Singh (@BJPRajnathSingh) March 31, 2016

Spoke to DG NDRF who apprised me of the situation at the accident site in Kolkata. NDRF teams have been rushed to the spot for rescue ops — Rajnath Singh (@BJPRajnathSingh) March 31, 2016

- CNN-IBN reports West Bengal Chief Minister Mamata Banerjee is rushing to the accident site

- Two units of NDRF are being rushed to Ganesh Talkies area of Kolkata to assist in the rescue work

#Visuals Taxis buried under the debris of the collapsed bridge near Ganesh Talkies in Kolkata pic.twitter.com/rFfDXhecDp — ANI (@ANI_news) March 31, 2016

- An ANI reporter at ground zero says there are scores of dead bodies buried under the debris with many more trapped

Monumental tragedy. Rescue ops on.Many feared dead. Chief Sec/Home Sec at site. CM headed back to Kol immediately.This is the update I have — Derek O'Brien (@quizderek) March 31, 2016

- An Army unit has reportedly joined the rescue operation at the flyover collapse site in Kolkata

Desperate attempts being made to lift up fallen bridge near Ganesh Talkies in Kolkata pic.twitter.com/hmfoAAT5e4 — ANI (@ANI_news) March 31, 2016

Initial story

An under-construction flyover collapsed on a busy street in north Kolkata at around 12 noon on Thursday.

At least 10 people were feared dead in the incident that took place near Ganesh Talkies in Girish Park area, ANI reported.

Rescue operations are underway in full swing, reports said.

An eyewitness told ANI as many as 150 people could be buried under the debris.

Another eyewitness said concrete on the section of the bridge that collapsed was laid only last night.

The focus of the rescue operation is currently on rescuing those trapped under the debris.

Distressed to learn about an under construction bridge collapse in Kolkata. Have instructed the WB unit to assist in the rescue operation. — Amit Shah (@AmitShah) March 31, 2016

TV visuals showed several vehicles, including cars and trucks, crushed under the debris.

The flyover was being built in a densely-populated area and was under construction for over five years now, reports said.