A delivery person was injured after a tree branch struck him while he was riding his bike in Red Hook Monday afternoon, Nov. 16, 2015. View Full Caption DNAinfo/Nikhita Venugopal

RED HOOK — A delivery person was critically injured after a branch struck him while he was cycling by a tree being taken down by Parks Department contractors, according to FDNY officials and the agency.

The man, believed to be in his 50s, was riding on Pioneer Street near Coffey Park at about 1 p.m. when the branch struck him, a fire department spokesman said.

The tree was being taken down by an “outside contractor” doing post-Hurricane Sandy work, according to a statement from the Parks Department.

“Our thoughts are with the individual injured in this unfortunate incident,” the Parks Department said in the statement. “NYC Parks is conducting a thorough investigation of this incident, and the outside contractor responsible for this work has been suspended while we investigate.”

Parks Department workers are supposed to use cones, caution tape and workers on the ground to warn pedestrians about about any possible falling debris.

It was not immediately clear if the contractors had used anything to block off the area.

The delivery person was taken to New York Methodist Hospital in very serious condition. It's not immediately clear which company he works for.

Earlier this year, DNAinfo reported that the city was spending $3.2 million to remove and replace 3,600 Sandy-damaned Brooklyn trees.

Coffey Park reopened this past summer after being closed for more than a year for a $2.3 million reconstruction project.

Residents are advised to report any damaged or fallen trees to 311 or through the tree service request system on the Parks Department website.