"Had a telephonic conversation with the PM and apprised him of the rescue operations being carried out by the NDRF in Kolkata (sic)," Singh tweeted.
The Prime Minister is in the US to attend the the two-day Nuclear Security Summit.
The Home Minister said his ministry was constantly monitoring the situation and rescue operation in Kolkata.
In a statement, the Home Ministry said the National Disaster Response Force (NDRF) has deputed seven teams (about 315 personnel) for rescue operations at the site in North Kolkata.
At least 18 people were killed, over 60 others injured and many trapped as portion of an under-construction two km flyover collapsed on a congested road intersection in Kolkata today.