D owned and operated the M/V Otterburn under time charter to Federal Commerce and Navigation Co., a Canadian corporation affiliated with P. Federal Commerce hired P to prepare the vessel to receive a cargo of grain. The crew had commenced the installation of 'grain feeders.' The boatswain, acting on the instructions of the ship's Chief Officer, 'winged out' the deep tank lids -- that is, pulled them outboard into the wings of the 'tween deck. No railing, wire, or guard of any kind was placed around the resulting deep tank openings. On the third day of work, a group of P's stevedores, supervised by Gordon McNeill, arrived at approximately 7 o'clock to continue with carpentry work McNeill was last seen shortly after 8 a.m. At 8:45 a.m. his lifeless body was discovered lying at the bottom of one of the deep tanks. There were no witnesses to his 30-foot fall. McNeill's widow filed a claim for benefits under the Act. McNeill's widow filed a claim for benefits under the Act. The potential total liability of P for these payments is approximately $70,000. The widow also filed a maritime wrongful death action against D. iD answered the complaint, denying that McNeill's death had been caused by its negligence or by its failure to furnish a seaworthy vessel. D commenced a separate action in the same court against P seeking indemnification for any judgment it might be required to pay in the wrongful death action. P filed an answer denying most of the allegations of the libel and also filed a counterclaim seeking damages from D for 'all sums which have been paid or will be paid' as compensation benefits to McNeill's dependents. The counterclaim alleged that D, as owner and operator in control of the Otterburn, owed the stevedoring contractor 'the duty of providing and maintaining a safe place to work so that injury to the employees . . . would be avoided.' D moved to dismiss the counterclaim for failure to state a cause of action. Each party then filed a motion for summary judgment on its claim and counterclaim. The court denied D's motion for summary judgment but it did grant the motion to dismiss P's counterclaim. The court concluded that the employer's rights provided by the Longshoremen's and Harbor Workers' Compensation Act are exclusive and 'prevent him from maintaining an independent cause of action against the third party tortfeasor.' The Court of Appeals affirmed. P's' sole remedy is by subrogation under the Act. P appealed.