Hannibal Board of Public Works crews are installing extensions on the city’s flood gates Thursday.

BPW officials say that crews began constructing the wooden extensions Wednesday and plan working into the evening Thursday to install the extensions on the six Hannibal flood gates.

The extensions add about two feet to the concrete and gate portion of the flood wall, raising it to 34 feet.

The latest crest prediction has the Mississippi River cresting at 29 feet in Hannibal Friday evening.