Search and rescue efforts are underway in coordination with local authorities. In addition to tug boats out of Singapore, RSN Fearless-class patrol ships RSS Gallant (97), RSS Resilience (82), RSN helicopters and Singaporean Police Coast Guard vessel Basking Shark (55) are currently in the area to render assistance. 

Large scale SAR operation for 10 missing sailors after the collision between USS McCain and Alnic MC - Image courtesy of Chief of Navy - PTL/twitter

An MH-60S helicopter from the amphibious assault ship USS America (LHA 6) are in the area providing search and rescue assistance. An additional MH-60S helicopter and MV-22 Osprey are expected to arrive soon.

Alnic MC is a Liberian-flagged 600-foot oil and chemical tanker with a gross tonnage of 30,000.

Initial reports indicate John S. McCain sustained damage to her port side aft. Damage control efforts continue while the extent of damage is being determined. The incident will be investigated.

Update: Large SAR operation for 10 missing sailors after collision between USS McCain and Alnic MC near Singapore (VIDEO)
Caption: Damage on USS McCain's hull after the collision with tanker Alnic MC - Image courtesy of Chief of Navy - PTL/twitter
Caption: Large scale SAR for 10 missing sailors of USS JohnSMcCain off Johor coast involving RMN vessels and help from MMEA, RMAF and Marine Police

VesselFinder video representation of Alnic MC movements prior the collision with USS McCain:

Video showing the damages on USS McCain’s hull: