Our capital allocation in the first quarter, we repaid $108 million of debt and we returned $331 million to shareholders, including $129 million of share repurchases.
The vast majority of our 48,000 team members work in our mills and conversion plants each and every day, and their health and safety remains our most important responsibility.
Our team is also making strong progress to develop and deliver multiple streams of earnings initiatives to achieve the $350 million to $400 million in incremental earnings and accelerated growth by the end of 2023.
We delivered EBITDA of $730 million and free cash flow of $423 million despite the $80 million pre-tax earnings impact from the winter storm in the Southern U.S. Revenue increased by more than $100 million sequentially, primarily driven by price realization in our Packaging and Global Cellulose Fibers businesses.
First quarter operating earnings were $0.76.
The winter storm impacted pre-tax earnings by $80 million or a $0.15 impact to operating EPS.
Mill and box system performance was solid and helped mitigate the impact of the winter storm, which was a cost headwind of $55 million to operations.
Maintenance costs increased sequentially, and we expect to complete about 65% of our maintenance outages in the first half of the year.
Input costs were unfavorable, which included a $20 million cost impact from the storm, mostly for energy and raw materials such as starch and adhesives.
We lost 145,000 tons of containerboard production due to the winter storm.
We had nearly 30 box plants in Texas, Louisiana and Mississippi affected by the storm, which impacted our box shipments in the quarter.
Our November increase is essentially implemented fully with the $131 million first quarter realization.
Operations and cost includes about $55 million impact from the winter storm, about half of which is due to unabsorbed fixed costs and the balance is related to repairs and higher distribution costs.
We did defer about $30 million of maintenance outages from the first to the second quarter due to the significant production loss resulting from the winter storm.
We expect to complete about 75% of our planned maintenance outages for packaging in the first half of the year.
Input costs were a significant headwind in the quarter, including about $20 million related to the winter storm due to higher energy, distribution and raw materials in our mill system and box plants.
Nondurables, excluding food and beverage, represents about 30% of U.S. box demand across a wide range of consumer and industrial products.
In the first quarter, we improved adjusted EBITDA by nearly $20 million compared with last year.
After the sale, the EMEA packaging business will have two recycled containerboard mills, 21 box plants and two sheet plants.
Operations and costs improved sequentially, driven by the nonrepeat of the $20 million write-off in the fourth quarter as well as solid operations and good cost management.
These improvements were partially offset by about $10 million of higher seasonal energy consumption and an FX loss at our mill in Canada.
Operations and costs improved on solid operations and good cost management, as well as a favorable FX in Brazil of about $10 million.
Fixed cost absorption improved with economic downtime decreasing by 40,000 tons sequentially across the system.
The joint venture delivered $49 million in equity earnings in the first quarter with an EBITDA margin of nearly 35%, driven by higher average pricing.
And lastly, in April, we saved a $144 million dividend payment from Ilim, which is $44 million higher than the estimate we provided last quarter.
We expect price and mix to improve by $75 million on realization of our March 2021 price increase.
Volume is expected to decrease by $10 million on lower seasonal demand in Spain and Morocco as the citrus season winds down.
Operations and costs are expected to improve by $15 million, with the full recovery of the winter storm impact partially offset by higher incentive compensation accruals related to a stronger outlook.
Staying with Industrial Packaging, maintenance outage expense is expected to increase by $77 million.
And input costs are expected to increase by $20 million due to higher OCC, energy, raw materials and distribution costs.
In Global Cellulose Fibers, we expect price and mix to increase by $100 million on realization of prior price movements.
Volume is expected to increase by $5 million.
Operations and costs are expected to decrease earnings by $10 million.
Maintenance outage expense is expected to decrease by $10 million, and input costs are expected to be stable.
We expect price and mix to increase by $25 million.
Volume is expected to increase by $5 million.
Operations and costs are expected to decrease earnings by $10 million due to the nonrepeat of foreign currency gain in Brazil during the first quarter.
Maintenance outage expense is expected to increase by $22 million, and input costs are expected to increase by $5 million.
And in the first quarter, we reduced debt by $108 million.
We also returned $331 million to shareholders, including $129 million of share repurchases, which represented about 2.6 million shares at an average price of $50.28.
And lastly, in the first quarter, we monetized about $400 million of our stake in Graphic Packaging.
After that transaction, we now hold about 7.4% ownership in the partnership.

Summary:
First quarter operating earnings were $0.76.