During the fourth quarter, we continued to execute our downsizing plans, first disclosed in October, including closing various facilities and scrapping equipment.
In addition, we reduced headcount by approximately 21% since the end of the second quarter.
During the fourth quarter, we recorded additional impairment and other charges of $10.6 million related primarily to severance and underutilized assets, bringing the total of impairment and other charges to $82.3 million in 2019.
For the fourth quarter of 2019, revenues decreased to $236 million compared to $376.8 million in the prior year.
Adjusted operating loss for the fourth quarter was $17.3 million compared to an operating profit of $19.7 million in the fourth quarter of the prior year.
Adjusted EBITDA for the fourth quarter was $23.2 million compared to EBITDA of $61.7 million in the same period of the prior year.
For the fourth quarter of 2019, RPC reported a $0.07 adjusted loss per share compared to a $0.06 diluted earnings per share in the prior year.
Cost of revenues during the fourth quarter of 2019 was $176.9 million or 75% of revenues compared to $274.4 million or 72.8% of revenues during the fourth quarter of 2018.
Selling, general and administrative expenses decreased to $36.8 million in the fourth quarter compared to $40 million in the fourth quarter of the prior year and this was due to lower employment costs.
Depreciation and amortization expense was $40.3 million during the fourth quarter of 2019, a decrease of 5.2% compared to $42.6 million in the prior year.
Technical Services segment revenues for the quarter decreased 38.7% compared to the same quarter of the prior year.
Excluding impairment and other charges, we incurred an operating loss of $17.2 million in the fourth quarter of 2019 compared to 19.9% [Phonetic] operating profit in the prior year.
Our Support Services segment revenues for the quarter decreased 13.2% compared to the same quarter in the prior year.
Operating profit in the fourth quarter of 2019 was $1.2 million compared to $2.5 million in the prior year.
On a sequential basis, RPC's fourth quarter revenues decreased 19.5% to $236 million from $293.2 million in the third quarter due primarily to pronounced seasonally lower activity levels and slightly lower pricing.
Cost of revenues during the fourth quarter of 2019 decreased by $48.3 million or 21.5% due to lower activity levels and our cost reduction actions.
As a percentage of revenues, cost of revenues decreased from 76.8% in the third quarter to 75% in the current quarter due primarily to a favorable job mix within RPC's pressure pumping service line.
Selling, general and administrative expenses decreased to $36.8 million during the fourth quarter of the current year compared to $42.6 million in the prior quarter.
RPC generated an adjusted operating loss of $17.3 million during the fourth quarter of 2019 compared to an adjusted operating loss of $21 million in the prior quarter.
Our adjusted EBITDA was $23.2 million compared to adjusted EBITDA of $22.8 million in the prior quarter.
Our Technical Services segment revenues decreased by 55.6% [Phonetic] or 20.3% to $218.9 million in the fourth quarter.
The Technical Services segment incurred a $17.2 million operating loss in the current quarter compared to an operating loss of $18.2 million in the prior quarter.
Our Support Services segment revenues in the fourth quarter were $17.1 million compared to $18.8 million in the prior quarter.
Operating profit was $1.2 million in the fourth quarter compared to $1.6 million operating profit in the prior quarter.
At the end of the fourth quarter, RPC operated 10 pressure pumping fleets.
At year-end '19, RPC's pressure pumping fleet totaled approximately 735,000 hydraulic horsepower.
Fourth quarter 2019 capital expenditures were $41.4 million and the full-year total of $250.6 million and we currently estimate 2020 capex to be approximately $80 million.
Despite the challenging environment during 2019 and approximately $250 million of capital expenditures, we ended the year with $50 million in cash and no debt.

Summary:
During the fourth quarter, we continued to execute our downsizing plans, first disclosed in October, including closing various facilities and scrapping equipment.
During the fourth quarter, we recorded additional impairment and other charges of $10.6 million related primarily to severance and underutilized assets, bringing the total of impairment and other charges to $82.3 million in 2019.
For the fourth quarter of 2019, revenues decreased to $236 million compared to $376.8 million in the prior year.
For the fourth quarter of 2019, RPC reported a $0.07 adjusted loss per share compared to a $0.06 diluted earnings per share in the prior year.
On a sequential basis, RPC's fourth quarter revenues decreased 19.5% to $236 million from $293.2 million in the third quarter due primarily to pronounced seasonally lower activity levels and slightly lower pricing.