NEW DELHI, Feb. 23 (Xinhua) -- Four laborers were killed and two others critically injured Monday after a 50-meter-long concrete slab of a corporation-owned building collapsed in the southern Indian state of Kerala, officials said.

Six workers were trapped under the concrete and were pulled out by the locals. Though they were immediately rushed to a nearby hospital by locals, four of them succumbed to their injuries, a police official said.

A probe into the incident is underway. ■