The crane and the 400-tonne concrete slab it had been lifting toppled early on Sunday morning causing a partly-built bridge to collapse.
Two cars, two trailers of Metro and a bus were damaged in the incident, which killed a construction worker and the bus driver.
The Delhi Metro ferries more than 700,000 passengers daily over a transit network of 65 km.
Work is currently underway to construct another 125 km of metro network before the 2010 Commonwealth Games.
The Delhi Metro Rail Corporation is investigating the incident.