On 9 December 1999 a United States Marine Corps CH-46 helicopter crashed into Pecos and sank while participating in a training mission. Seven of the 18 personnel on board the helicopter were killed in the accident. As routine procedure following an accident, members of the crew were subjected to drug testing. Captain Mark LaRochelle, the ship's Master, failed the initial and secondary drug tests and was subsequently relieved of command and fired from the Military Sealift Command. Following his dismissal from MSC, his US Coast Guard license was revoked.

https://en.wikipedia.org/wiki/USNS_Pecos_(T-AO-197)