A cracked building is seen in ­­Kolkata, India, on Sept. 4, 2019. About 350 residents were evacuated after several buildings collapsed or cracked due to the ongoing underground tunnel construction work for a metro railway project. (Photo: Xinhua)

People move their belongings during an evacuation in ­­Kolkata, India, on Sept. 4, 2019. About 350 residents were evacuated after several buildings collapsed or cracked due to the ongoing underground tunnel construction work for a metro railway project. (Photo: Xinhua)

Security personnel and engineers work near a collapsed building in ­­Kolkata, India, on Sept. 4, 2019. About 350 residents were evacuated after several buildings collapsed or cracked due to the ongoing underground tunnel construction work for a metro railway project. (Photo: Xinhua)

A collapsed building is seen in ­­Kolkata, India, on Sept. 4, 2019. About 350 residents were evacuated after several buildings collapsed or cracked due to the ongoing underground tunnel construction work for a metro railway project. (Photo: Xinhua)

People move their belongings during an evacuation in ­­Kolkata, India, on Sept. 4, 2019. About 350 residents were evacuated after several buildings collapsed or cracked due to the ongoing underground tunnel construction work for a metro railway project. (Photo: Xinhua)